It is inevitable that innocent people have been jailed as a result of evidence being withheld from defence lawyers – with the possibility that thousands of cases have been affected, a former chief prosecutor said.

On Tuesday, the Crown Prosecution Service (CPS) revealed that issues with disclosure had been identified in 47 of 3,637 rape and serious sexual assault cases in England and Wales that were reviewed between January and mid-February.

But former director of public prosecutions Lord Macdonald said it was likely that disclosure problems had also affected other cases – and part of the problem was due to Government cuts.

“There is no reason at all to suppose that these disclosure failures are restricted purely to sex cases,” he said.

“I am sure they are to be found across the entire calendar of criminal cases and I think, given what we have seen in this CPS review … it is quite inevitable that there are some innocent people in prison today because of disclosure failures.”

He told BBC’s Newsnight it was “impossible to say” how many but the review suggested problems in 1-2% of cases.

“That’s thousands of people, so it is really of the utmost importance that the CPS, the police and the Government grip this – it is very important to underline the Government have some responsibility here as well, the level of cuts to the funding of the CPS in recent years has been really quite intolerable.”

He warned: “If you cut a service to the bone then the service that it provides is going to suffer and the Government needs to acknowledge that.”

The current director of public prosecutions Alison Saunders has pledged to apologise over failures in the 47 identified rape and serious sexual offence cases where evidence was withheld.

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.

The cases 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.

Ms Saunders told the Justice Select Committee: “I feel every single failure. It’s not something that we want. We have been very clear about where our failings are. We will apologise for those.”

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.”

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.

Liam Allan apology
The trial of Liam Allan was halted at Croydon Crown Court on December 14 (David Mirzoeff/PA)

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.

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.