Det Insp Webster admitted he made errors of judgement

Det Insp Anthony Webster told a pre-trial hearing that he failed to properly record his notes of the confession from suspect Peter Williams.

He broke down in the witness box and was eventually given sick leave.

Williams was later found guilty at Stafford Crown Court of murdering the 64-year-old jeweller.

The detective's admission came at a hearing a month before the jury was sworn in.

He did say that but how I have recorded it wasn't correct Det Insp Webster Nottinghamshire police

He was asked by Crown Prosecutor Gregory Dickenson QC about an alleged confession Williams made in January 2004.

Williams was being questioned at Oxclose Police station about other matters and, according to Det Insp Webster's pocket book notes, he admitted being in the jewellers when an accomplice shot Marian Bates.

The officer told the pre-trial hearing that Williams had said: "I went into the jewellers... The next thing I heard was a shot. I didn't know he was going to shoot anybody."

Unprompted the Det Insp Webster then began to make a series of admissions himself, at one point saying: "He did say that but how I have recorded it wasn't correct."

When Mr Justice Gibbs asked him to clarify his comments, the 26-year veteran said he made the notes a couple of days after he had spoken with Williams.

'Sleepless nights'

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... the last 18 months of this investigation seems a complete blur."

He said he had "driven" the inquiry while his boss was "trapped in a lot of other things".

The detective said: "I've had numerous sleepless nights in relation to coming here today... That's why I've got to say I have made errors.

"Although I believe these men are guilty I cannot stand here and perjure myself."

Det Insp Webster apologised to his colleagues, the prosecution and Marian Bates' family, whom he said he had let down.

"I don't think I set out to mislead but I don't think I have been good enough in my job. There are numerous things I have done wrong in this investigation - I have let the Bates family down," he said.

He appeared to choke back tears while testifying until eventually he could not continue.

The defence did not cross examine him and the judge ruled his evidence should not go before the jury.

The court later heard he had been diagnosed with a severe depressive illness.