Can a complainant’s phone be examined during a criminal investigation?

Written 24th April 2024 by Saskia Abbot

With the vast growth in the usage of digital devices, this question can present challenges for criminal investigations. Examining a complainant’s phone during an investigation and obtaining relevant material may be an important feature in the case that may assist the investigator and prosecution in making a charging decision, by providing more context to the facts of the case and help get to the truth of the matter.

A charging decision could include the accused’s matter being no further actioned (NFA), it does not necessarily mean that a charge will be brought.

There are various documents that set out the governing of obtaining of materials from certain devices, including a complainant’s, and also outlines the legislative and regulatory framework that should be adhered to.

The relevant information can be found in varying documents, however some of the following has been briefly outlined below and sets out to assist an investigation.

The Attorney General’s Guidelines on Disclosure 2024

The Attorney General Guidelines on Disclosure 2024 were published on 29 February 2024 and will come into effect from 29 May 2024. They will replace the existing guidelines on disclosure and supplementary guidance on digital material. The guidelines have been updated and expand upon the guidance currently in place in relation to digital material.

These guidelines have been issued for investigators, prosecutors and defence practitioners in relation to disclosure, they highlight the principles that should be adopted when the disclosure regime is applied. Investigators should pursue and engage with prosecutors all reasonable lines of inquiry and the defence should engage with the prosecution, including pre-charge, where appropriate and may request any relevant material that could reasonable assist their case. 

Reasonable lines of inquiry

A reasonable line of inquiry, is one that points either towards or away from a suspect. What is reasonable will depend on the circumstances of the case and consideration should be had of the prospect of obtaining relevant material.

Relevant material

Relevant material is and material that has some bearing on any offence under investigation or any person being investigated or on the surrounding circumstances of the case, unless it is incapable of having any impact on the case. Relevance is a decision that requires an exercise of judgment on the part of the investigator. In the context of a complainant’s phone, this may contain text messages, audio and/or visual evidence or social media evidence that may be relevant in assisting the investigation. For example, in a coercive and controlling allegation made by a complainant, obtaining a complainant’s phones and examining it may could shed light on the relationship and may show it in a different light the that alleged, it may assist the accused.

Annex A

Digital material is intended to supplement the guidelines, its aim is to set out a common approach to be adopted whether seeking to obtain digital material from a complainant, suspect or witness. This annex aims to set out how relevant material and material meeting the test for disclosure can be identified and should be disclosed to the defence, whilst also not being too onerous on the investigator and prosecutor, it also provides guidance on handling sensitive and personal information.

Statement by Solicitor General, Robert Courts KC MP, summarised, said:

“Advances in modern technology have substantially increased digital material and created significant challenges for investigators, procedures and defence practitioner alike. It is right that we address these challenges and strengthen the disclosure regime. I have updated the Attorney Generals guidelines – specifically guidance on digital materials. Changes to the current guidelines include encouraging better engagement between Prosecutors and Defence at both Pre and Post charge stages”.

Annex A contains exactly the same subsections as the previous guidelines, however the final section on the ‘scheduling of digital material’ adds far more detail and requires a much more onerous compliance. This will encourage far better engagement between the prosecution and the defence.

The Criminal Procedure and Investigations Act 1996 (CPIA)

Under section 3(1)(a), a prosecutor must disclose to the accused any prosecution material which has not previously been disclosed to the accused and which might reasonably be considered capable of undermining the case for the prosecution against the accused.

The Disclosure Test, is set out in the Attorney General’s Guidelines on Disclosure.

Material that might reasonable be considered capable of undermining the case for the prosecution against the accused, or of assisting the case for the accused. 

If when examining a complainant’s phone as part of an investigation, it becomes apparent that it contains material capable of undermining the case against the accused, it should be disclosed to the defence, if it meets the disclosure test.

What should the prosecution consider when seeking to obtain material?

It is however important that any intrusion into a complainant’s personal life cannot be speculative and unnecessary and in the case of R v CB and Mohammed [2020] EWCA Crim 790, issue of principle that investigators and prosecutors should consider when seeking to obtain material were outline and included the following –

  • There must be good cause to seek to review a witness’s digital material.
  • Consideration should be given as to whether the relevant messages or other communications are available on the suspect’s digital devices, within the witness or complainant’s social media accounts or elsewhere.
  • Could a discrete part of the messages be reviewed as part of a reasonable line of inquiry?
  • A complainant should be kept informed and updated of the use that is proposed to be made of the phone.
  • If a complainant does not provide and continues not to provide the investigator to access to the phone or other device, the reasons for this should be carefully considered as the issue may become the ability for a fair trial.

Balance between the right to a fair trial and the right to family and private life.

Investigators and prosecutors need to be aware of the fine balance to be struck between the right to a fair trial under Article 6 of the European Convention of Human Rights (ECHR) which provides “Everyone is entitled to a fair and public hearing within a reasonable time by an independent and impartial tribunal established by law” and Article 8 ECHR which provides – “Everyone has the right to respect for his private and family life, his home and his correspondence”.

This is a balance that is needed when a suspect has a right to a fair trial and the complainant (and witnesses) have a right to privacy. To comply with Auricle 6 ECHR, it may be necessary to request personal and/or private information from a complainant to pursue a reasonable line of inquiry, during the course of an investigation, this would include looking into a complainant’s phone. However, when seeking to obtain this material, this may engage an individual’s rights under Article 8 ECHR.

To balance Article 6 and Article 8, the following principles, in summary, should be followed as set out in the Attorney Guidelines for Disclosure.

  • Collecting and processing personal or private material must be in accordance with the law and must be strictly necessary and proportionate.
  • For it to be in accordance with the law and necessary, the investigator must be pursuing a reasonable line of inquiry in seeking to obtain the relevant material.
  • Reasonable maybe informed by the investigator or defendant and must be reasonable, reasonableness being assessed on a case by case basis.
  • Investigators needs to consider what relevant material is required and what is the least intrusive method to obtain it, the scope of review should be open and transparent.
  • Disclosure of material to the defence should meet the test for disclosure under the CPIA. 

What happens when a complainant refuses access to their phone?

In some cases, a complainant may consent to the examination of their phone. However, if consent is refused, the investigators or police may need consider other legal avenues to access the material contained on the device. It is also important that the police comply with PACE (1984) when examining a phone because if they fail to do so, it could deem any evidence obtained in the circumstances inadmissible at trial.

In summary, the examination of a complainant’s phone during a criminal investigation is possible, but it must be conducted in accordance with the law and must respect and individual’s right to privacy.

Where there the is a conflict between Article 6 ECHR and Article 8 ECHR, the right to a fair trial is an absolute right under Article 6 and any unavoidable intrusion into privacy rights is likely to be justified as long as it is it necessary and proportionate.

Contact our criminal pre-charge investigations solicitors

If you would like to discuss how we can proactively assist you in relation to your case at the pre-charge investigation stage, please contact our new enquiry team either by email to, or by telephone on 020 3883 6790 (London) or 0161 834 1515 (Manchester) or by completing the form below and our new enquiry team will contact you.

Saskia Abbot

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