Sherlock Holmes star Benedict Cumberbatch's relation was charged with Romsey stabbing

But now it has been revealed how an ancestor of actor Benedict Cumberbatch was suspected of a gruesome murder in Hampshire – in a case that would have tested the skills of the great detective himself.

Research has revealed that the great-greatuncle of the 37-year-old, who stars as Holmes in the BBC series Sherlock, was arrested and charged with stabbing a friend to death near Romsey in 1893.

Henry Ventham, just 14 at the time, was accused of murdering Frederick Betteridge while the pair were picking blackberries on a country lane in the village of Awbridge.

A fierce row is said to have broken out, resulting in a fatal knife wound for 14-year-old Betteridge, who was found with a blade still lodged in his chest.

Benedict’s ancestor pleaded not guilty when he went before a judge at Hampshire Assizes in Winchester.

Ventham, who came from a family of farmhands, was dramatically cleared after a third boy told the jury in evidence that the incident was a tragic accident and that Betteridge had accidentally run on to the knife.

The jury accepted the version of events and Ventham was found not guilty of both murder and manslaughter.

The remarkable story is well documented in the Daily Echo’s archives of the Hampshire Advertiser from 1893, appearing under the headline “The Romsey Stabbing Case”.

The report finished with the comment: “His Lordship…was quite content with the view they had taken of the case (applause in court).”

The 120-year-old story was unearthed after researchers at the family history website findmypast.co.uk examined Cumberbatch’s past.

Debra Chatfield, a family historian at the website, said: “Though Benedict’s paternal history is well known and documented online, this startling discovery is quite the revelation; pieced together through old criminal records, newspaper articles and court records.

“His great-great-uncle was not convicted but it just shows how many curve balls family history can throw at us.”