The notable collapse of a series of rape trials could endanger future convictions of genuine rapists because of reduced public trust in the justice system, the former head of the judiciary has warned.

Lord Judge, who was lord chief justice in England and Wales from 2008 to 2013, said juries may start doubting the quality of evidence presented to them in court after several high-profile rape cases collapsed owing to blunders by police and the CPS.

The comments to the Times were made after a rape case against Oliver Mears, a 19-year-old student at Oxford University, was dropped on Friday after police accepted making errors during the investigation.

“The recent examples in cases involving alleged sexual crime are alarming, both for all the individuals concerned and for public confidence in the administration of criminal justice generally,” Judge told the newspaper.

“It is at least possible that from time to time juries, alarmed as everyone else by these cases, may wonder, even in an apparently strong case, whether they have been provided with all the admissible evidence.

“These events may reduce the prospects of conviction even when the allegation is genuine.”

On Friday, Surrey police announced a full review of all ongoing rape cases, admitting that errors had been made in the Mears case.

“We accept that there were flaws in the initial investigation. It was not expedient and the investigator did not examine the victim’s digital media during the initial stages of the investigation or follow what we would consider to be a reasonable line of enquiry,” the force said in a statement.

A review of the case produced evidence that supported the Oxford student’s account, causing prosecutors to drop the case.

Mears spent two years on bail before the CPS decided to charge him in June 2017, prompting criticism from the judge, Jonathan Black.

The case is one of many that has collapsed in recent weeks due to errors from the CPS and the police.

On Monday a rape trial against Samson Makele was halted after his defence found mobile phone images showing him apparently cuddling in bed with his accuser.

In December last year, the Metropolitan police announced a review of all sexual assault investigations after two rape cases were dropped against Isaac Itiary and Liam Allen.

The Guardian  20 Jan 2018