Historians are attempting to secure a royal pardon for a convicted killer hanged in Oxford 200 years ago.

Giles Freeman Covington, a 23-year-old seaman, was executed in March 1791 for murdering a Scottish pedlar, David Charteris, whose body was found in a ditch in Nuneham Courtenay, near Oxford.

Covington denied the crime, but was convicted on the evidence of local criminal Richard Kilby, an army deserter also wanted in connection with the killing.

On his arrest, Kilby offered to turn King's Evidence in return for a Royal Pardon, claiming Covington and an accomplice, Charles Shury, were the killers.

Records show that after the death sentence was carried out, Covington's corpse was taken for dissection at a lecture in the Anatomy School at Christ Church. His bones were cleaned and wired together to be used as a teaching aid, a role the skeleton fulfilled for more than 70 years.

For the next century, Covington stood in a glass case in Oxford's University Museum, simply labelled "Englishman".

Almost 20 years ago, a researcher saw the name Giles Covington inscribed on his lower jaw and his skeleton was given to the city museum where it is now displayed.

But curator John Lange has now decided that after years as a public spectacle, Covington should be granted a full Christian burial. Mr Lange has already secured the agreement in principle of Wolvercote Cemetery to bury him, and because of the dispute surrounding his arrest, four years after the murder of the pedlar, he also hopes to clear his name and secure a royal pardon.

Old documents have been studied by historian Mark Davis, who is writing a book about the Covington case. He and Mr Lange hope to convince the Home Office that justice is long overdue.

Mr Lange said: "The main motivation was to highlight interest in one of the more popular exhibits in the museum and for more people to know about it, rather than being simply a skeleton in a case in a dusty museum.

"We always recognise the difficulty of trying to overturn a conviction, but by doing the research for his book, Mark and I wanted to highlight the case and open up the debate before putting forward arguments to the Home Office."