Det Insp Webster broke down in court after admitting his mistakes

The Independent Police Complaints Commission found there was no evidence of criminal conduct or misconduct by any officer involved in the trial.

In a 2003 pre-trial hearing, Det Insp Anthony Webster admitted bungling his handling of an alleged confession.

Mr Webster broke down during the murder trial and was given sick leave.

'Positive message'

The allegations of misconduct came to light after Mr Webster interviewed Peter Williams, later convicted of murdering Marian Bates, at Oxclose Police Station about another matter.

According to Mr Webster's notes, Williams admitted being in Mrs Bates' jewellers when an accomplice shot her. But Mr Webster continued saying he made the notes a couple of days after he had spoken to Williams.

He said: "My work in this investigation has not been up to the highest standards...I have made errors of judgement in relation to my pocket book...Although I believe these men are guilty, I cannot stand here and perjure myself."

In his report, senior investigator Malcolm Niblo said there were "lessons for Nottinghamshire force to learn" in relation to best practice in timely completion of pocket notebooks.

A spokesman from Nottinghamshire Police Federation welcomed the ruling.

"We are truly heartened that he has been completely exonerated by the totally independent IPCC.

"This will send a very positive message to honest, committed, professional officers throughout the organisation."