Tragedy has struck the family of Cressida Bonas, Prince Harry’s girlfriend, after her party-loving stepfather, who friends say was a major influence on her life, was found dead on Friday, after allegedly taking an overdose of prescription pills.

Wiltshire Police told the Daily Beast the death is not being treated as suspicious.

The body of Christopher Shaw, 76, a former Grenadier Guards officer and merchant banker, was discovered in his flat in Salisbury by the owner of the property.

"He was regarded by Cressida as a father figure," a friend of Miss Bonas told the Daily Beast. "He was married to her mum for the formative years of her childhood. She will be devastated by this news."

Prince Harry's office at Kensington Palace declined to make any comment, and it is not known whether Harry will accompany Cressida to the funeral. He and Cressida are still together but he may be afraid of creating a media circus.

Mr Shaw, a former head boy at Eton, who is believed to have been suffering from a terminal illness, had recently returned from a holiday in Cuba and celebrated his birthday on New Year's day.

Mr Shaw was known to enjoy the high life. He married Lady Mary-Gaye Curzon, Miss Bonas’s wild, blue-blooded mother, in 1996, when Cressida was 7, celebrating his wedding to her mother with a party for 300 of their friends. They split four years later.

A friend told the Sun: “He enjoyed the high life and probably wasn’t able to fund that any longer.”

His landlord, who found the body, told The Times that Mr Shaw had been in good spirits and was shocked by the discovery. “He’s a friend of mine, and I was completely devastated to find him dead,” he said.

The Sun is reporting that the death is being regarded by Wiltshire Constabulary as a suspected suicide resulting from an overdose of pills and that the coroner was awaiting the results of toxicology tests.

However the force declined to confirm this to the Daily Beast today.