Prosecutors were warned nearly two years ago that lawyers were under increasing pressure to boost rape convictions and were consequently wrongly charging men with sexual offences.

A report published in February last year highlighted a series of alarming failings in how the Crown Prosecution Service (CPS) and police handled serious sex cases.

The 108-page review by HM Crown Prosecution Service Inspectorate warned of a “vicious circle” as police sometimes handed incomplete case files to CPS lawyers already struggling with an immense backlog of casework.

The report authors said they identified a number of cases where lawyers who should have sent inadequate files back to detectives demanding they obtain more evidence to build a case but instead chose to charge a suspect because they were under “undue pressure”.

The report, called Thematic Review of the CPS Rape and Serious Sexual Offences Units, gave a worrying snapshot of an underfunded and overstretched legal system.

Its emergence comes as there were calls for a national review of rape cases after the Metropolitan Police launched an urgent review of every live rape case it is investigating following the collapse of two trials in London after it emerged officers had failed to disclose vital evidence that pointed to the defendants’ innocence.