Police investigations into sexual offences will be slowed by the challenge of dealing with masses of digital information, a senior officer has said.
The warning from the chairwoman of the National Police Chiefs' Council, Sara Thornton, comes after the collapse of a series of trials because digital information undermining the case was released at a late stage to the defence.
Ms Thornton said that, in future, investigators will have to discuss with prosecutors at a early stage in any case what reasonable lines of inquiry might arise from information stored on phones, tablets and laptop computers.
This could involve the use of hi-tech artificial intelligence to comb through vast digital archives, with some police forces farming out the job to private companies, she suggested.
Writing in a blog on the NPCC website, Ms Thornton said: "We are challenged by the sheer volume of data we all hold in 2018, and therefore the many, many more potential lines of inquiry.
"So, we must co-operate, acting with fairness and impartiality, and this might mean practical conversations with complainants and suspects at the start of the process to ask them 'Is there anything in your phone that's relevant to the case?'"
And she said: "Getting this right means we are asking investigators to do more at a time when we have a shortage of detectives and many other complex demands.
"We must be honest that this may slow investigations in the short term and forces will have to consider moving resources."
Ms Thornton stressed that police could not simply hand over to defence lawyers the records of all calls, texts and other messages made by those involved in a case.
This could deter some victims from coming forward for fear of having their personal life exposed in court, she warned.
"We cannot allow people to be put off reporting to us because they fear intrusion into their lives and private information that's not relevant to the crime being shared in court - the digital equivalent of the tired trope of women in short skirts 'asking for it'," said Ms Thornton.
"This is why the idea of handing all the unused material to the defence won't work - it would go beyond what is reasonable and proportionate."
She said police were looking into the availability of "clever tech" to speed searches of digital records.
And she told BBC Radio 4's Today programme that some forces were already contracting the job out to private firms.
"Given the significant increase in digital material, forces have really struggled to cope to provide sufficient capacity," she said.
"Some do it in-house, some have looked to the private sector to help with that.
"For many years, forensic analysis has been done by experts who work in private companies under strict regulation."