Police are investigating whether a British billionaire’s daughter-in-law was playing a drinking game with a Belize police chief when he was fatally shot, a new report says.

Jasmine Hartin, 38 — an American married to the son of businessman Lord Michael Ashcroft — had been boozing it up with San Pedro Superintendent Henry Jemmott for a couple of hours before his body was found in the waters off San Pedro Island with a single gunshot wound behind his right ear Friday, the Times of London reported.

Probers now believe that the pair were playing a game with Jemmott’s pistol on the pier before things went horribly awry, a police source told the paper.

Hartin was found "deeply distressed and shaking" by a security guard who overheard a shot fired, the newspaper reported.

MARINE FATHER'S SALUTE TO SON GOES VIRAL: REPORT

Jemmott’s service weapon was retrieved from the pier, police said.

The victim’s sister, Marie Jemmott Tzul, 55, said she received word Sunday night that charges will be filed against Hartin in his death, the Daily Mail reported.

"I got a call. I was informed that she will be charged [Monday], but they did not say what she was going to be charged with," Tzul told the news outlet.

Edward Fitzgerald, a London-based lawyer who is not involved in the case, said that if Jemmott was mistakenly killed as a result of "pistol play," it’s likely that Hardin will be hit with manslaughter charges, the Times reported.

He said manslaughter convictions in Belize come with stiff penalties, with the most serious resulting in 25-year prison sentences.

But he added, "There is a chance in this type of case that the authorities could determine that the death was completely accidental and no charges would be brought."

Belize Police Commissioner Chester Williams said, "We have to look at the investigation with an open mind, but so far, we have not had any indication to suggest that there was any third actor."

CLICK HERE TO GET THE FOX NEWS APP

He said Hartin, who was taken into custody and has refused to cooperate with investigators, is the prime suspect.

"In the absence of an explanation … she would have to be treated as the killer," he said.

To read more from the New York Post, click here.