SANTA FE, United States (AFP) — Hollywood legend Gene Hackman had likely been dead for over a week when he and his wife were found lifeless in their New Mexico home, the local sheriff said Friday.

Authorities launched a probe into what they said were the “suspicious” deaths of Hackman, 95, and his classical pianist wife Betsy Arakawa, 63, as questions swirl over how the beloved actor could have died.

Santa Fe Sheriff Adan Mendoza told reporters Friday the partially mummified bodies had no external injuries but initial tests revealed “both individuals had tested negative for carbon monoxide”.

Early suggestions, including from Hackman’s family, were that they could have been overcome by fumes.

But, said Mendoza, tests had begun to narrow down a possible date of death.

“An initial interrogation was conducted of Mr Hackman’s pacemaker. This revealed that his last event was recorded on February 17, 2025,” he said.

“I think that is a very good assumption that was his last day of life.”

The bodies of the Oscar-winning star of “The French Connection” and his wife were found on Wednesday, after emergency services were called to the scene when maintenance workers had been unable to access the sprawling property.

First responders found the door unlocked and open, and pills scattered next to Arakawa’s body, which was in the bathroom.

Hackman’s body was found in another room, fully clothed, with sunglasses next to his body, indicating a sudden fall.

A German Shepherd was found dead in the bathroom, and two other healthy dogs were at the house.

Mendoza said as they waited for the results of toxicology tests, which might shed some light on the tablets by Arakawa’s body, investigators were now trying to piece together a timeline.

That included looking through planners and cell phones and searching for any video that might give hints to the couple’s movements over the last few weeks.

But, he said, it was a complicated task, compounded by their low profile.

“I think everybody here understands that they were very private individuals and a very private family,” he said.

In a statement issued Thursday, Hackman’s family said they were “devastated by the loss.”

“He was loved and admired by millions around the world for his brilliant acting career, but to us he was always just dad and grandpa,” daughters Elizabeth and Leslie Hackman and granddaughter Annie Hackman said.

“We will miss him sorely and are devastated by the loss,” they added.

Hackman, a two-time Academy Award winner, was credited for intense performances of everyman characters inspired by his troubled upbringing, notching up dozens of movie credits extending into his 70s.

He is perhaps best known as vulgar New York cop Jimmy “Popeye” Doyle in the 1971 crime thriller The French Connection — for which he won an Oscar for best actor.

He won another golden statuette two decades later for best-supporting actor for his portrayal of the brutal small-town sheriff “Little Bill” Daggett in the 1992 western Unforgiven.