Mr Lyons was a regular in The Saddle Inn public house in Anfield, where Mr Barrett was also well known character.

According to timesheets obtained from Portus & Rhodes Ltd, Mr Rigby and Mr Coufopoulos were both at work on the morning of March 9 1992, the very day that Mr Barrett contacted London literary agent Doreen Montgomery with the immortal words, "I've got Jack the Ripper's diary, would you be interested in seeing it?"

Mr Smith said: "Barrett was a colourful local character who was always boasting about being an author, so when the electricians at the house found this book, they believed he was the man who would be able to help them sell it to a publisher.

"The truth was that Barrett's only significant literary achievement was to write occasional puzzles for the weekly TV children's magazine, Look-In.

"Barrett had a highly impetuous nature. Just seeing or being told about the signature at the end of the diary would have been enough for him to reach for the phone.

"He was not very literate and the idea that he would have been capable of producing such a sophisticated and credible forgery is not remotely plausible."