Highwayman Dick Turpin may not be buried in the grave marked with his name, an academic has suggested.
Turpin was hanged in York in 1739 and accounts from the time suggest he was buried in St George's graveyard in the city, where there is a large headstone.
James Sharpe, Professor Emeritus of Early Modern History at the University of York, has written "Dick Turpin: The Myth of the English Highwayman".
He said, "Contemporary accounts tell of how Turpin's body was taken from the gallows and buried in St George's graveyard.
"However, body-snatchers attempted to steal the body, so the coffin was filled with slaked lime to render it unusable to the body-snatchers and reburied.
"While researching my book I became increasingly sceptical that the grave visible today actually contains Dick Turpin's remains. It is unlikely that a convicted felon would be buried in a marked grave and all of the other gravestones in the small graveyard date from after Turpin's death."
Prof Sharpe was asked to look further into the mystery by The York Dungeon, which is opening a new show about the highwayman.
The professor said: "My investigation of new sources shows that there was no Dick Turpin headstone in St.George's graveyard prior to 1918, meaning the current headstone is a recent addition. Wherever Dick Turpin is buried is a mystery, but it seems very unlikely that he's under the current headstone."
Stuart Jarman, general manager at The York Dungeon, said, "As part of the research for our new Dick Turpin show we consulted with renowned historian and Dick Turpin scholar Professor James Sharpe, at the University of York.
"At The Dungeons we are renowned for presenting fascinating aspects of history in a scary, fun and entertaining way, but we always strive for historical accuracy. There is a mystery surrounding what happened to Dick Turpin's body, which we'd like to get to the bottom of."
He said: "After nearly 300 years it is amazing to think there may be another twist to the Dick Turpin story, and one we hope to look deeper into in the future."