Jeremy Corbyn has criticised moves to get rape victims to turn over their mobile phones to the police.

The Labour leader’s intervention came after rape complainants were told they risked prosecutions against their attackers not going ahead unless they allowed their digital devices to be looked at.

Mr Corbyn said the “disturbing” practice risked allowing more rapists to get away with their crimes.

Consent forms, which ask permission to access messages, photographs, emails and social media accounts, have been rolled out across the 43 forces in England and Wales.

The move is part of the response to the disclosure scandal, which rocked confidence in the criminal justice system when a string of rape and serious sexual assault cases collapsed after crucial evidence emerged at the last minute.

Mr Corbyn tweeted: “We need to do all we can to support victims of sexual violence to come forward and report cases to the police.

“With rape and sexual assaults already under-reported, this disturbing move risks letting more rapists get away with it.”

Police and prosecutors say the forms are an attempt to plug a gap in the law, which cannot force complainants or witnesses to disclose their phones, laptops, tablets and smart watches.

Director of Public Prosecutions Max Hill said digital devices will only be looked at when they form a “reasonable line of inquiry” and only “relevant” material will go before a court if it meets “hard and fast” rules.

“If there’s material on a device, let’s say a mobile phone, which forms a reasonable line of inquiry, but doesn’t undermine the prosecution case and doesn’t support any known defence case, then it won’t be disclosed,” he said.

And the Crown Prosecution Service said: “It is not true that complainants in rape cases must automatically hand over personal data on their digital devices or run the risk of the prosecution being dropped. Mobile phone data, or social media activity, will only be considered by the police when relevant to an individual case.”

But privacy campaign group Big Brother Watch has dubbed the measures “digital strip searches” and said “treating rape victims like suspects” could deter people from reporting crimes.

Northumbria Police and Crime Commissioner Dame Vera Baird said the forms are just part of the problem as police and prosecutors look to harvest third-party material, such as school records and medical notes.

“The police are really saying ‘If you don’t let us do this, the CPS won’t prosecute’,” she said.

Prime Minister Theresa May’s spokesman told a Westminster briefing the issue was complex.

He said: “Clearly, this is a complex area and, while disclosure is an important component of the criminal justice system, to ensure a fair trial, the police have acknowledged that the use of personal data in criminal investigations is a source of anxiety and that they understand the need to balance a respect for privacy with the need to pursue all reasonable lines of inquiry.”

New Director of Public Prosecutions
Max Hill has defended use of the consent forms (CPS/PA)

In the lead-up to trials, police and prosecutors are required to hand over relevant material that can undermine the prosecution case or assist the defence.

The regime came under sharp focus from the end of 2017 after a string of defendants, including student Liam Allan, then 22, had charges of rape and serious sexual assault against them dropped when critical material emerged as they went on trial.

The CPS launched a review of every live rape and serious sexual assault prosecution in England and Wales and, along with police, has implemented an improvement plan to try to fix failings in the system.

Some 93,000 officers have undertaken training while police hope artificial intelligence technology can help trawl through the massive amounts of data stored on phones and other devices.

In rape and sexual assault cases, prosecutors now use disclosure protocols previously used in terror trials.

The digital consent forms can be used for complainants in any criminal investigations but are most likely to be used in rape and sexual assault cases, where complainants often know the suspect.

The forms state: “Mobile phones and other digital devices such as laptop computers, tablets and smart watches can provide important relevant information and help us investigate what happened.

“This may include the police looking at messages, photographs, emails and social media accounts stored on your device.

“We recognise that only the reasonable lines of inquiry should be pursued to avoid unnecessary intrusion into the personal lives of individuals.”

Liam Allan apology
Liam Allan’s trial collapsed after crucial evidence emerged (David Mirzoeff/PA)

Police and prosecutors have sought to reassure victims of crime that only material relevant to a potential prosecution will be harvested, but the forms state even information of a separate criminal offence “may be retained and investigated”.

They also state: “If you do not provide consent for the police to access data from your device you will be given the opportunity to explain why.

“If you refuse permission for the police to investigate, or for the prosecution to disclose material which would enable the defendant to have a fair trial then it may not be possible for the investigation or prosecution to continue.”

Mr Allan, now working with miscarriage of justice campaign group Innovation Of Justice, said it was “completely understandable” that rape complainants might not wish to hand over data stretching back a long time before the alleged offence and with no relevance to the allegation.

But he told BBC Radio 4’s Today programme that, in his case, he “did not even think to ask” for details of the complainant’s phone contacts with friends around the time of the alleged assault.

“That was some of the valuable evidence,” said Mr Allan. “If we have to ask for these things, not knowing how the process works, then we are at a disadvantage and it’s not a fair trial.

“The consent form is a good step, as long as it’s carried out in the right way, as long as it’s not trawling through unnecessary information.

“I was innocent. I was asked to give over my phone. Does that mean I lose all my rights to privacy because I was accused?

“It has to work both ways … We deserve the same rights until the point of conviction.”

The Information Commissioner’s Office said it has launched an investigation into use of data extraction technology on the mobile phones of suspects, victims and witnesses.