Northumbria Police and Crime Commissioner Vera Baird says police plans to make rape victims hand over their mobile phones could mean serial offenders go free.
Victims are being told they must hand over their mobiles to police or risk prosecutions against their attackers not going ahead.
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.
Dame Vera said the forms were 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.
"It is a real concern that people will be put off making a complaint in the first place if it's widely thought they are going to have to hand over lots of personal data - everyone lives on their phones, particularly teenagers.
"We need to treat complainants in rape cases with exactly the same fairness and support that we treat complainants in any other kind of case and not single them out and require them to disclose their life history to convince the authorities they are fit for the criminal justice system."
She said there was a 'public safety issue' that could see serial rapists walk free if victims decided not to come forward because they fear every element of their private life being examined.
"This is not consent," she warned.
"This is an authority figure telling you to sign a form as soon as you have finished an interview which may be reliving what is one of the most horrific experiences of your life. If you don’t agree that’s the end of the case and you’ve just done the interview for nothing.
“The evidence is already there - those victims who decline to grant access are having their cases dropped. Home Office figures show the proportion of rape cases being prosecuted nationally had dropped to a low of just 1.7 percent. For victims to sign away their privacy to hand over their mobiles will see this figure drop even further”.
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.
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 would only be looked at when it forms a 'reasonable line of enquiry' and only 'relevant' material would 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 enquiry, but doesn't undermine the prosecution case and doesn't support any known defence case, then it won't be disclosed," he said.
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 enquiry should be pursued to avoid unnecessary intrusion into the personal lives of individuals."
Rachel Krys, co-director of the End Violence Against Women Coalition, said the forms reinforced 'prejudices and barriers' against rape victims: "We have an extremely serious problem with prosecuting rape in this country and it is a fact that most rapists get away with it," she said.
"Part of the reason for this is that investigations too often focus on women's character, honesty and sexual history, despite rules which are supposed to prevent this, instead of the actions and behaviour of the person accused.
"There is no reason for rape investigations to require such an invasion of women's privacy as a matter of routine.
"There is a pressing public interest in prosecuting this very serious and harmful crime, and victims shouldn't be coerced into sacrificing their privacy to get the crimes against them investigated.
"Anything which gets in the way of the system working for all of us and bringing rapists to justice must be challenged."