The Metropolitan Police Commissioner has apologised and admitted failings after an inquiry found a string of errors in the force's botched investigation into an alleged VIP paedophile ring.

Retired High Court judge Sir Richard Henriques analysed the Met's handling of eight historical sex crime investigations, including Operation Midland, Operation Yewtree and Operation Vincente.

The £2.5m Operation Midland probe, surrounding claims that boys were sexually abused by highly placed public figures more than 30 years ago, closed in March of this year.

Sir Bernard Hogan-Howe admitted today that Operation Midland “should have tested the credibility of the complainant more rigorously” and talked of his “professional and personal dismay”.

Northumbria Police has said it is investigating the sole complainant, “Nick”, for perverting the course of justice.

Speaking more frankly on the subject than previously, the retiring 59-year-old said on Tuesday: “I accept, on behalf of the Metropolitan Police, accountability for these failures as I accept accountability for failures in any of our operations and investigations.

“It is a matter of professional and personal dismay that the suspects in the investigation were pursued for so long when it could have been concluded much earlier.

“I am today issuing a public apology to Lord Bramall, Lady Brittan and Harvey Proctor for the intrusion into their homes and the impact of Operation Midland on their lives.The public identification of suspects compounded the harm of our investigative failures.

“They have all suffered as a result of the investigation and our description of the allegations as ‘credible and true’. We should not have said this, and we should have tested the credibility of the complainant more rigorously before conducting the searches."

The high-profile Operation Midland investigation surrounded accusations made by a single alleged victim known as Nick, claiming the "savage" abuse led to the deaths of three boys.

The late prime minister Sir Edward Heath, who took Britain into the European Union in 1973, was investigated Stephen Hird/PA Wire (PA)

Nick said he witnessed a group of powerful men in the 1970s and 80s abusing young boys in central London locations including a Dolphin Square flat near Westminster Palace.

Doubts gradually grew over the investigation into former Home Secretary Leon Brittan Getty (Getty)

The Henriques Report, which took eight months to put together, pinpointed 43 errors in the Operation Midland investigation and contained 25 recommendations for lawmakers and policing nationally.

The errors included: believing complainant Nick was a credible person for too long; saying publicly that the allegations were credible and true; obtaining search warrants with flawed and incomplete information; and not closing the inquiry sooner.

It also said the “failings of a few officers” should not undermine the Met Police's reputation, and it reserved praise for Operation Yewtree – the investigation into and stemming from Jimmy Savile's abuse.

Sir Hogan-Howe concluded his statement by trying to explain the doomed Operation Midland investigation, citing media pressures, public profile of suspects and an alleged government cover-up.

Deputy Labour Party leader Tom Watson has repeatedly refused to apologise for his role in the VIP sex abuse inquiry, after he initially lobbied police to investigate, saying: “When anyone is accused of multiple sexual crimes by numerous, completely unrelated sources, the police have a duty to investigate, no matter who it is.”