Skip to main content

Accessibility controls

Main content area

International Enquiries

Updated: 2 August 2022|Legal Guidance, International and organised crime


This guidance provides an overview of how prosecutors can obtain evidence from overseas for use in criminal investigation or proceedings in England and Wales. More detailed process guidance can be found on the Casework Hub.

For guidance on other types of international cooperation please see: Joint Investigation Teams, Proceeds of Crime Legal Guidance, Extradition Legal Guidance. In addition, the Home Office has produced guidance for foreign authorities on seeking evidence from the UK.

  • Prosecutors can obtain evidence from overseas using mutual legal assistance (MLA). This takes the form of a formal International Letter of Request (ILOR) issued by a designated prosecuting authority or a Court.
  • MLA with all EU Member States (except Denmark and Ireland) has been replaced by the European Investigation Order (EIO).
  • A prosecutor is not always required to obtain evidence from overseas; often it can be obtained by investigators through police cooperation channels. This is often referred to aspolice to police informal cooperation or mutual administrative assistance (MAA).
  • The appropriate mechanism to be used to obtain evidence from overseas generally depends on the type of assistance being sought and the domestic legislation of the country from which the assistance is sought.
  • Investigators and prosecutors should be alert to the need to obtain evidence from overseas as early as possible and keep this under review as the case progresses.

Using international cooperation

Increasingly, our cases have an international dimension and prosecutors may find themselves seeking evidence and information, the surrender of suspects or defendants from overseas, participating in a Joint Investigation Team (JIT) and seeking to restrain assets and enforce confiscation orders abroad.

When should obtaining evidence from overseas be considered?

Prosecutors should consider whether it is necessary to obtain evidence from overseas as early as possible and keep this under review as the case progresses. The evidence needed from overseas and the method used to obtain it should form part of the case strategy. Requests for evidence/assistance from overseas should only be issued where to pursue the line(s) of enquiry is reasonable, necessary and proportionate for the purpose of the investigation or proceedings.

Who should request the evidence?

Evidence can be obtained from abroad in a variety of ways. The UK’s domestic legislation regarding obtaining evidence from overseas is widely drafted. Section 7 Crime (International Cooperation) Act 2003 (CICA) permits an application to be made by ILOR but does not require it. The method you will need to use in a particular case will depend on the type of evidence/assistance you are requesting (see below) as well as the country you are seeking evidence from.

Wherever possible, police to police channels should be used to obtain the assistance sought. A prosecutor should make the request where the evidence can only be obtained from the country concerned through MLA (using an ILOR) or, for participating EU Member States, through the EIO. Where the requested country is unable to provide the assistance via police to police channels, an ILOR or EIO should be considered and, as long as the material (whether intelligence or evidence) is being sought in relation to an ongoing criminal investigation and represents a reasonable line of enquiry, the prosecutor should issue an ILOR or EIO. Where a request from a prosecutor is not necessary, cooperation between domestic police and an overseas police authority can and should be used.

Requesting Mutual Legal Assistance (MLA)

Section 7 CICA provides that designated prosecutors and courts (on application of a non-designated prosecuting authority or, where proceedings have been instituted, on behalf of the person charged) can issue ILORs. Crown Prosecutors are designated under the Crime (International Cooperation) Act 2003 (Designation of Prosecuting Authorities) Order 2004.

Section 7 CICA also sets out the circumstances in which an ILOR can be issued and for what purposes. A designated prosecuting authority can only issue a request if:

  • It appears to the authority that an offence has been committed or that there are reasonable grounds for suspecting that an offence has been committed, and
  • The authority has instituted proceedings in respect of the offence in question or it is being investigated.

The UK is party to a number of bilateral and multilateral MLA treaties. As a matter of domestic law it is not necessary for an MLA treaty to exist between the UK and the requested country in order to make a request under section 7 CICA, although requests are more likely to be successful where a treaty basis exists. Where a treaty does exist, it should be cited in the ILOR as the legal basis for requesting evidence/assistance.

Under section 8 CICA, ILORs can be sent direct by a prosecutor to the relevant judicial authority in the receiving State (this is known as direct transmission). In practice direct transmission only applies to some countries that have implemented the Council of Europe Convention on Mutual Assistance. Please check the Casework Hub to establish whether or not you can send an ILOR directly. The European Judicial Network (EJN) Atlas tool allows you to identify the competent local authority in each EU Member State to receive and execute an ILOR (or, where applicable, an EIO). However, note that section 74 Proceeds of Crime Act 2002 directs that ILORs seeking the recognition and enforcement overseas of either a restraint and/or confiscation order cannot be sent directly (whether within the EU or otherwise) and must be sent via the Home Office.

All requests which cannot be sent directly overseas must be sent via the Home Office for onward transmission:

UK Central Authority Tel: +44 (0)207 035 4040

Home Office Fax: +44 (0)207 035 6986

2nd Floor, Peel Building Email:

2 Marsham Street London SW1P 4DF

Drafting an ILOR

A letter of request is a formal, written legal document that must comply with both domestic statutory requirements and also any relevant treaty.

It is a stand-alone document and must be easily understood and capable of execution by the requested state without further consultation and without the need for UK prosecutors or investigators to attend the other country. It is essential that the foreign authority is given all the information it will need to decide whether assistance should be given and how to do so. Colloquialisms and jargon should be avoided, as should unnecessary use of technical language. It is best to avoid long sentences and lengthy paragraphs. This is particularly important when the request requires translation. The aim is to produce an easy to read document which immediately conveys to the reader what is required, why, when and the form that it is required in.

A precedent ILOR is available.

See also the Country Information pages on LION for details of any applicable international instruments under which individual States agree to provide MLA, translation requirements, and details of where to send the ILOR.

Issues to consider

The following is a non-exhaustive list of issues that should be considered when drafting an ILOR:

  • Data Protection - Where the ILOR contains personal data and the ILOR is being transmitted outside the EU, the transfer must comply with Chapter 5, Part 3 of the Data Protection Act 2018.
  • Risk Assessments - Where the request appears to engage risk issues because of where it is being sent (for example an FCO Human Rights Priority Country), the information in the request, and/ or the type of evidence requested, the Home Office may require a risk assessment before transmitting the ILOR.
  • Timescales - There are no obligations in international law to execute an ILOR within a specific timeframe. Prosecutors should be realistic about how long it may take to get a response. The more novel, complex or resource-intensive the request, the longer it will take to carry out. Care should be taken not to overcomplicate requests or ask for extraneous matter as this can add further delay. You should set out in the ILOR the reason for any particular urgency (e.g. defendant remanded in custody, immediate risk to individuals, risk of dissipation of assets etc.) and provide the dates of any deadlines which need to be met.
  • Confidentiality - It is usual policy for central and executing authorities to neither confirm nor deny the existence of an MLA request/EIO, nor disclose any of its content outside government departments, agencies, the courts or enforcement agencies in the UK without the consent of the requesting authority, except where disclosure is necessary to obtain the co-operation of the witness or other person concerned.
  • Dual Criminality - Some states may not be able to provide assistance if the request arises from conduct which does not constitute an offence in the requested state, particularly where the assistance you are seeking requires the use of a coercive measure overseas. A conductbased approach should be taken, i.e. the conduct underlying the alleged offence is considered when assessing dual criminality, rather than seeking to match the exact same term or offence category in both jurisdictions.
  • Translation - Once the letter of request is completed it may be necessary to translate the ILOR into an official language of the requested country. Please check the Country Information pages on the LION website to confirm whether a translation is required. It is the responsibility of the police/investigating authority to arrange and pay for the translation.
  • Costs of Execution - The cost of executing a request is generally borne by the executing authority overseas. Exceptions include costs of an extraordinary nature (which should be agreed in advance) such as payment of the fees and reasonable expenses of expert witnesses, the costs associated with video-conferencing and the costs of transferring persons in custody.
  • Admissibility - The normal rules of admissibility apply to evidence obtained from overseas. This is also the case where evidence is obtained via other forms of co-operation.
  • Collateral Use - Under Section 9 CICA evidence obtained by the UK may not be used for any purpose other than that specified in the original request without the consent of appropriate overseas authority. It is therefore important when drafting the ILOR not to unnecessarily limit the purposes to which the evidence obtained may be put.
  • Reciprocity - The UK does not generally require reciprocity but would expect assistance from countries which are parties to relevant bilateral or international agreements with the UK. Reciprocity is required in all requests for assistance in tax matters.

Types of assistance

The extent of assistance which can be provided through informal cooperation varies between countries and is dependent upon factors including:

  • Type of assistance sought;
  • Domestic law of the requested state;
  • The existence of applicable legal instruments including treaties, conventions and any applicable EU Framework Decisions and Directives;
  • Relations between the country concerned and the UK.

It is not possible to give a definitive list of enquiries which will always require an MLA request. The following non-exhaustive list notes classes of evidence that usually require an MLA request:

MLA Request Likely
  • Banking evidence - obtaining account information and documentary evidence from banks
  • Computer evidence - obtaining internet records and contents of e-mails (although certain information from US based companies can be obtained directly from them)
  • Coercive measures - requests for search and seizure and other requests that involve a coercive measure that would require a court order in a domestic case in England and Wales
  • Television links at trial - requesting a link for a witness to give live evidence at a trial in England and Wales from another country
  • Witnesses - obtaining a statement from a non-voluntary witness
  • Confiscation and restraint of property

Examples of enquiries which can often be undertaken via informal cooperation, rather than MLA, include the following non-exhaustive list of enquiries:

MLA Request Unlikely
  • Previous Convictions
  • Public Records
  • Voluntary witness statement - Note, the law/procedure of the other state must be respected and, where necessary, prior authority obtained from the relevant foreign authority for any witness to be approached

The police must always have permission from the receiving country to travel overseas on official business whether on enquiries as a result of an ILOR or for informal enquiries.

Issuing a European Investigation Order (EIO)

On 31 July 2017 the European Investigation Order (EIO) became the legal framework applicable to the gathering and transfer of evidence between the UK and participating EU Member States (all Member States except the Republic of Ireland and Denmark). The UK implemented the EIO under The Criminal Justice (European Investigation Order) Regulations 2017.

Assistance from participating Member States should now be sought using the EIO. Assistance from Denmark and Ireland should continue to be requested via ILOR.

The EIO uses a standardised template and (unlike ILORs) imposes time limits for recognition (30 days) and execution (90 days). An EIO may be issued:

  • in respect of evidence sought for investigations and criminal proceedings;
  • where it is necessary and proportionate for the purpose of the investigation or proceedings for the EIO to be issued; and
  • the investigative measures sought could be carried out in the UK.

EIOs can be issued by a designated prosecutor or by a court. Even where the evidence is sought by a designated prosecutor, the appropriate issuer may be the court. This will depend on the power (court, prosecution or investigative authority) exercised in an equivalent domestic case. Generally speaking, where that power is considered coercive, the power to issue will lie with the court, for example production orders, searches of premises and witness evidence via live link:

Court required to issue the EIO
  • Production Order
  • Search Warrant
  • Evidence via Live Link
  • For evidence/assistance sought by a defendant (where proceedings have been instituted)

EIOs should be sent directly to the competent authority in the EU Member State concerned. See the EJN Atlas to identify the appropriate authority in each EU Member State competent to receive and execute an EIO.

See also Types of Assistance section above for examples of when, depending on the jurisdiction concerned, an EIO or direct police cooperation are likely to be appropriate.

Transfer of proceedings

For the purpose of this guidance transfer of proceedings means a formal request by the CPS to another jurisdiction to take over a prosecution (note separate arrangements exist to transfer reporting a crime).

A formal request for transfer of proceedings is issued by a CPS prosecutor and transmitted overseas by the Home Office. This is not a request for assistance within the meaning of section 7 CICA and there is no domestic legislative basis for transferring proceedings from England Wales to another jurisdiction. However, a number of international agreements provide a basis for transfer of proceedings:

  • Article 21 (Laying of Information) - Council of Europe Convention on Mutual Assistance in Criminal Matters 1959 (1959 Convention);
  • Article 47 - UN Convention against Corruption ('UNCAC');
  • Article 8 - UN Convention against Illicit Traffic in Narcotic Drugs and Psychotropic Substances ('Vienna Convention');
  • Article 21 - UN Convention against Transnational Organised Crime 2000 ('UNTOC'); or
  • Bilateral MLA / Extradition Treaties

Drafting and transmission

Where a transfer of proceedings is being considered, informal contact should always be made with the other jurisdiction before a formal request is issued.

A request to transfer proceedings must be considered and drafted by a prosecutor using the template form and addressed to the appropriate overseas authority. In addition, sufficient material should be prepared (and if necessary, translated) to enable the overseas authority to decide whether or not to accept the transfer.

A completed, authorised request (and supporting material) must be submitted to the Home Office (UK Central Authority) for transmission.

If the requested state makes a request for new evidence (i.e. that which was not already gathered or available at the time the transfer request was made) that cannot be fulfilled via police to police cooperation, an MLA request or EIO should be made by the overseas authority and sent to the Home Office (to be executed by the relevant law enforcement agency).

Non-criminal proceedings

There are occasions where a CPS prosecutor may be asked to assist with overseas enquiries by the police or others even though the cooperation contemplated does not directly relate to criminal proceedings. In such a situation, CICA does not apply and an ILOR (or EIO) cannot be issued. A prosecutor can still often make a request to a foreign authority for particular information or assistance via a standard business letter. The prosecutor should simply and courteously explain why they are making the request, on whose behalf, what material/assistance is requested and why. For example:

  • Inquests - The coroner may have requested information, e.g. a copy of an autopsy report or witness statements, only to be told by the foreign authority that the request must be made by a judicial or prosecution authority. In order to assist the coroner and to ensure the desired outcome, the prosecutor may write to the foreign authority requesting the information. The prosecutor should note in brief the role of the coroners court in England and Wales, and the purposes to which the supplied information will be put. This course of action should only be taken if it is clear that the other country will not respond without our assistance and where the Coroner has specifically agreed that we make the request on their behalf.
  • Family liaison visits - Ensuring the wellbeing of victims and witnesses is an important part of the CPSs commitment to victim care and for case management. Occasionally, a foreign authority will only accede to a request for officers to travel overseas for family liaison visits following a formal letter from a judicial or prosecution authority. Where that happens the prosecutor may send a business letter.


International enquiries are a powerful and often crucial tool in the investigation and prosecution of offences. It is important to note that the approach to disclosure in the international context is consistent with the disclosure principles generally.

For guidance on the obligations on the prosecutor in respect of material held overseas, see paragraphs 46-54 of the Attorney General’s Guidance on Disclosure 2022 ("International Enquiries "), and paragraphs 51–53 of the Judicial Protocol on the Disclosure of Unused Material.

The Guidance and the Protocol apply equally to the EIO as to other procedures for obtaining material from overseas.

Other resources

Further reading

Scroll to top