Nearly all criminal law practitioners have encountered a failure to disclose evidence in the past year, according to a survey which attracted over 1,200 responses.
The BBC commissioned a survey in conjunction with the Criminal Law Solicitors' Association, the London Criminal Courts Solicitors' Association and the Criminal Bar Association.
According to the findings, 97 per cent of respondents said they had witnessed disclosure of evidence failings in the past 12 months.
More than half (55 per cent) encountered these problems every day or every week and the failures were evenly split as occurring with the CPS or police.
At least four in ten practitioners encountered a disclosure failure in magistrates courts and 45 per cent were encountered in the Crown Court.
Nearly eight in ten said failures had delayed the trial, while more than eight in ten said failures put the defence under “unreasonable logistical or time pressure.”
Over half said the failures caused a case to collapse whilst a third said the failures resulted in possible wrongful conviction or miscarriage of justice.
Judge Gregory Perrins, sitting at Wood Green Crown Court in north London, said there had been "wholesale failure" by the prosecution over its disclosures of evidence in the case of Adrian Iordan, Anisoara Lautaru and new mother Petruta-Cristina Bosoanca.
The trio were originally arrested in connection with allegations of people trafficking and would have attracted lengthy custodial sentences had they been convicted.
Chris Henley, QC Vice Chairman of the Criminal Bar Association told Police Oracle the survey results do not surprise him and says disclosure problems are increasing.
He said: “I think training for forces and the CPS is really important and also the capacity to deal with inquiries in crucial cases.
“There has been a significant capacity problem obtaining material from, for example, mobile phones, with delays of six months in some cases, causing a strain on witnesses and people charged with offences.
“I think the government needs to prioritise obtaining extra capacity so all inquiries can be completed in a timely fashion.
“There is a genuine desire on all sides to get this right and we need to look at what needs changing to prevent this.
“In many case juries have lost confidence in criminal trials and also the wider public, which is no good from a policing point of view.”
The NPCC and the CPS have devised a new strategy to prevent future failings, including a review of training on disclosure and a cadre of specialist and experienced disclosure experts in every force.
The sharp rise in collapsed cases (70 per cent) has also prompted the Justice Committee to carry out an inquiry.
Chairman of the Justice Committee, Bob Neill MP, said: "There have been significant concerns that disclosure issues, not just in the Allan case but in many others, have resulted in inappropriate charges, unnecessary delays in court proceedings and potential miscarriages of justice.
“This raises serious and profound questions about the handling of cases by the police and CPS.
“We intend to investigate disclosure procedures fully to ensure they are fit for purpose and that the welcome steps proposed to address existing issues are sufficient to resolve them.”