Lady Brittan has condemned the police watchdog for clearing all officers involved in an operation which pursued claims of child abuse against her late husband, after an independent report accused police of dozens of errors in investigating the accusations.

The Daily Telegraph reported that the wife of the late Lord Brittan, the Jewish MP who served as Home Secretary from 1983 to 1985, described the system of investigating officers for misconduct, conducted by the Independent Office for Police Conduct (IOPC), as “fundamentally flawed.”

The accusations were subsequently found to have been fabricated by the accuser Carl Beech, who was revealed to have been a paedophile himself. Beech was charged with perverting the course of justice and jailed in July for 18 years.

An independent review, commissioned by the Metropolitan Police and conducted by retired High Court judge Sir Richard Henriques, of this investigation - Operation Midland - highlighted dozens of mistakes by officers in charge of investigating claims that former high-profile politicians had abused, tortured and in some cases killed children.

As part of the operation, two homes that belonged Lord Brittan were searched in 2015, weeks after his death.

Sir Richard's report said the police looked at correspondence, including condolence notes sent to Lady Brittan, as well as searching the properties’ gardens. The district judge who issued the search warrants later said police had “misled” him.

In another operation investigating a historic rape claim made against Lord Brittan, the peer was questioned while he was ill with terminal cancer. He died before he could be informed he had been cleared of that allegation.

The officer in charge of both operations has apologised for what he described as “the distress that has been caused to innocent people and their families".

A close friend told the Daily Telegraph it was an “incredibly difficult and distressing experience” for the peer’s widow.

"The failings of the police are clear for everyone to see in the report from Sir Richard Henriques and the account of Howard Riddle, the former district judge who says he was misled by police during Operation Midland”, they said.

"Yet the IOPC has found that nobody is to blame. Either the system is fundamentally flawed or we have reached a stage where innocent people can be traduced and have their lives ruined by the Metropolitan Police with complete impunity."