Sir Bernard's decision to quit after agreeing a contract extension was announced just weeks before Sir Richard's report was sent to Scotland Yard.

The summary findings of the internal inquiry are due to be published on Tuesday.

Mr Proctor added: "I made it clear he should never have got another year in the first place and as it turns out he has has served only half that time.

"Why did he accept the one year contract extension if he was planning to leave? Clearly he went once he knew which way the wind was blowing."

Mr Proctor, who is also calling for the full report to be made public, said other parties will call for the IPCC to investigate if the Met Police fail to do so this week.

Sir Richard, a former High Court judge, was asked by Sir Bernard Hogan-Howe, the Met commissioner, to examine the way in which Operation Midland had been handled after it collapsed amid controversy in March this year having cost almost £2m.

The claims of a Westminster paedophile ring were based on the word of one claimant, known only as "Nick", who named a number of VIPs.

After 16 months of investigation the police admitted that there was no evidence to support the claims and apologised to Bramall.