Detective Chief Superintendent Chris Gregg was accused by Irish writer Noel O'Gara of deliberately "stitching up" Sunderland man, John Humble, as the infamous writer of hoax letters and a tape recording purporting to be from the killer.

In March 2006, Humble was jailed for eight years after admitting four counts of perverting the course of justice by publishing the hoaxes and causing police attention to be drawn from the real inquiry into the Ripper's killing spree in the late 1970s.

But Mr O'Gara, author of a book on the Ripper - in which he claims the "real" killer is still on the loose - accused Mr Gregg of deliberately causing the conviction of an innocent man, being a party to the tampering with of DNA evidence and also the mistreatment of Humble in his interviews.

Mr Gregg launched a libel action last year and today, in a hearing at the High Court in London, the judge hearing it, Mr Justice King, entered "summary" judgment against Mr O'Gara.

He said the writer had no evidence to back up his claims and "no sources, other than his own imagination".

Mr Justice King said O'Gara had conducted a "persistent campaign of vilification" against Mr Gregg, who is in charge of all major investigations in West Yorkshire.

He ordered him to pay the full amount of the claim, which was limited to £50,000, within 12 weeks.

The judge also imposed an injunction on O'Gara, preventing him from repeating the libels, and ordered him to pay £10,000 in costs within 28 days on account of a bill which, pending full assessment, is estimated to exceed £30,000.