Call for Holmes: Conan Doyle is accused of betrayal and murder

Investigators are attempting to show once and for all that the creator of Sherlock Holmes was involved in a dark plot to bump off a former editor of the Daily Express - the man who should truly be acknowledged as the creator of the Hound of the Baskervilles.

In a bizarre scenario that Holmes himself might have appreciated, it is alleged that Bertram Fletcher Robinson was poisoned with laudanum, administered by his wife under the instruction of Conan Doyle.

The motive, the investigators allege, was to cover up the theft of the Baskervilles tale and silence the true source of the story. Next week the investigators will make a formal application to the Diocese of Exeter to dig up Fletcher Robinson's corpse. Officially the cause of death was typhoid.

Paul Spiring, a scientist coordinating the investigation, said: "If you take a purely objective, scientific view of our findings, the evidence of a cover-up is irrefutable."

Some of the allegations were outlined by the author Rodger Garrick-Steele in his book House of the Baskervilles, but Mr Spiring carried out his own investigations after becoming intrigued when he moved to the village of Ipplepen, where Fletcher Robinson is buried.

Conan Doyle and the journalist visited Dartmoor together, and Baskerville was the surname of Fletcher Robinson's coachman. A footnote to the first edition of Hound of the Baskervilles acknowledges his contribution: "This story owes its inception to my friend Fletcher Robinson who has helped me."

But the fullness of his debt became lost in later reprints. In a letter to his mother from Dartmoor, Conan Doyle says the book is already half complete - suggesting he may have been working from a manuscript presented to him by Fletcher Robinson.

The investigation team suggests that the journalist's wife may have tipped off Conan Doyle that her husband was unhappy that he was poorly remunerated for his efforts. He then suggested she should slip him laudanum, as he knew its symptoms were similar to typhoid. "We're not saying she was necessarily a co-conspirator in this, really more of a patsy," said Mr Spiring.

Holmes experts have dismissed the claims that Fletcher Robinson may have been the real author as "bunkum".