Police and prosecutors face a grilling by MPs after a review identified 47 rape and serious sexual offence cases where vital evidence was withheld from defence lawyers.
A national review was launched earlier this year after a number of rape cases collapsed in quick succession when it emerged that police and prosecutors had failed to pass key information to defence teams.
On Tuesday the Crown Prosecution Service (CPS) revealed that issues with disclosure had been identified in 47 of 3,637 cases in England and Wales that were reviewed between January and mid-February.
These included five where disclosure was the primary reason why the case had to be stopped.
In the remaining 42 there were additional reasons including communications data such as text messages, emails and social media being examined too late; a failure to get material from third parties such as medical or social services records; or new evidence emerging after charge.
Some 14 defendants were in custody at the time the decision was made to stop their cases.
Assistant Chief Constable Stuart Prior, Disclosure Lead for the National Police Chiefs Council (NPCC), said: "We've got to realise that this is about real people.
"Whether that is a person reporting a matter to us, whether it be a person as a witness, or whether it be somebody accused of an offence. That's incredibly traumatic, whatever aspect you look at.
"We've got to get disclosure right. We cannot allow mistakes to impact so greatly on people's lives as has been played out in the media over the past few months.
"Our whole criminal justice system is based on fairness - fairness of investigations, fair trials and we have to strive and provide that for all the people who come into the criminal justice system. We have got it wrong in too many cases."
In December and January a string of rape cases collapsed when it emerged that vital evidence had not been passed to defence lawyers.
The trial of Liam Allan was halted at Croydon Crown Court on December 14, and the prosecution of Isaac Itiary collapsed at Inner London Crown Court a few days later.
The following month the case against Samson Makele, 28, was halted at Snaresbrook Crown Court after his defence team unearthed key images from his mobile phone which had not previously been made available.
And Oxford student Oliver Mears, who had spent two years on bail, had the case against him dropped days before he was due to go on trial.
This sparked a national review by prosecutors of all live rape and serious sexual assault cases to see how many were affected by the same issues.
Gregor McGill, CPS director of legal services, refused to say if any lawyers are facing disciplinary action over the stopped cases, while Mr Prior said for officers or police staff it would be a matter for individual forces.
When asked about potential compensation claims, Mr McGill said "Just because a case has been stopped doesn't necessarily mean that anyone is at fault".
Director of Public Prosecutions Alison Saunders, Chief Constable Nick Ephgrave from the NPCC and Chief Executive of the College of Policing Mike Cunningham are due to give evidence to the Commons Justice Select Committee on Tuesday.
Ahead of the hearing Ms Saunders said: "Getting disclosure right is a fundamental part of a fair criminal justice system. Our analysis shows that in the vast majority of cases we are doing that.
"But there are cases where we are falling short, and that is unacceptable. I recognise the huge impact on individuals involved, and deeply regret every case where mistakes have been made."
A raft of measures are being brought in including a National Disclosure Improvement Plan including new training for prosecutors and police officers, measures to deal with disclosure at an early stage in legal proceedings and better technology to help investigators sift through vast amounts of communications data.
The CPS gave a regional breakdown of the 47 stopped cases as follows: two in Wales; four in the East Midlands; 23 in London; four in Mersey Cheshire; two in the North East; four in the North West; three in the South West; two in the West Midlands, and three in Yorkshire and Humberside.