In the courtroom, Michael Mansfield's eye for detail has helped forge his reputation as one of Britain's most eminent barristers. But a curious case involving the QC's memoirs and gruesome multiple murders that never happened have called into question his powers of recollection.
Mr Mansfield has been forced to change a section of his recently-published book and issue an unequivocal apology after a complaint from a convicted murderer he once represented.
John Bowden, who has been serving a life sentence for the killing of the park-keeper Donald Ryan since 1982, claimed that Mr Mansfield attributed crimes to him that he never committed – describing him as a serial killer who targeted homosexuals and alcoholics.
From his prison cell in HMP Glenochil, near Fife, Bowden, 53, wrote a letter of complaint to the barrister. And now Mr Mansfield, who has worked on some of Britain's most high-profile cases, including the inquests into the deaths of Princess Diana and Jean Charles de Menezes, has admitted his error and has agreed to change the book for all future editions.
The offending paragraphs are on page 173 of Mr Mansfield's book – entitled Memoirs Of A Radical Lawyer – in a chapter dealing with prison riots.
In the book, Mr Mansfield tells how, in 1983, he was called to Parkhurst high-security prison on the Isle of Wight after an assistant prison governor was taken hostage. The siege involved Bowden, whom Mr Mansfield describes as "a south Wales lad turned bad by drink and unemployment".
Mr Mansfield continues: "I had defended him at the Old Bailey in relation to what had become known as the Camberwell murders, a series of particularly grotesque and gruesome killings, which had involved carving up homosexuals or winos while they were still alive and freezing the cuts."
In fact, Bowden, has only ever murdered one man. He killed Donald Ryan in November 1980 and was ordered to serve a minimum of 25 years in prison. His original trial heard how he tortured Mr Ryan and cut up his body. The judge, Mr Justice Mars-Jones, said: "There was never a more terrible case of murder than this one."
In a series of letters to Mr Mansfield, Bowden complained: "Neither the police nor prosecuting authorities have ever claimed that I was responsible for any other murders."
He claims that Mr Mansfield's suggestion that he had multiple victims was an attempt to "spice up" his book. And goes on: "There is no other explanation as to why someone who boasts of possessing a forensic memory for details and facts should so outrageously misrepresent the truth concerning why I was imprisoned." In Mr Mansfield's apology, which will be sent to the parole board, the QC writes: "In the narrative describing the siege at Parkhurst I wrote that John Bowden was convicted of a series of murders that involved carving up homosexuals and winos.
"This is in fact untrue and is the result of a mistaken recollection on my part... There was never any claim or suggestion that during John Bowden's trial in 1982 that he or his co-defendants were responsible for more than one murder or that John Bowden had ever targeted a specific group of people. The error is entirely unintentional and has been corrected for all future editions of the book."
The letter, sent to Bowden via Lawrence Kershen QC, acting as an intermediary, makes clear that Mr Mansfield did not want the apology to be published.
But Bowden met this request with an unforgiving response. He said: "Can you believe the cheek of the man? So it's OK for him to write and publish blatant lies that are distributed around the world, but I must keep quiet and private when he finally admits that what he wrote about me was a load of shite."
A spokeswoman for Bloomsbury, the publisher of Mr Mansfield's book, confirmed that the section has now been changed for the paperback edition of the book, which was first published last September.
Bowden has had a chequered 28-year history in prison. As well as the siege in 1983, he has escaped twice and has successfully sued the prison authorities for mistreatment. His friend John McGranaghan said: "What John did was not nice, and no one is disputing that. But to say he is a serial killer who specifically sought out homosexuals and winos is just not true and unfair."
Another source close to the case added: "On the one hand I can see why people might not have any sympathy with a convicted murderer. But this guy is sitting in a prison cell and feels he has rehabilitated himself from a crime that happened nearly 30 years ago and is hoping to get parole soon."
Michael Mansfield is abroad and was unavailable for comment. Mr Kershaw, who is from the same chambers as Mr Mansfield, confirmed the letters were genuine but said he could not comment on the dispute for reasons of confidentiality.