Authorities are expected to release an update today regarding an investigation into the deaths of actor Gene Hackman and his wife, Betsy Arakawa, who passed away on Wednesday afternoon.

The Santa Fe Sheriff's Department is currently investigating the cause of death, with preliminary autopsies noting no signs of external trauma or obvious foul play.

In a search warrant request made by the Sheriff's Office, a deputy stated the circumstances were "suspicious enough in nature to require thorough search and investigation."

The couple's bodies were found in different rooms, with scattered medication next to Arakawa. Fire officials at the scene "did not locate signs of a carbon monoxide leak or poisoning," and a gas company found no issues during inspection of gas lines in and around the residence.

The head of New Mexico's medical investigator's office said that an examiner's final reports with cause of death can take four to six weeks to complete. Both carbon monoxide and toxicology tests have also been requested.

"We want to make sure that we get the investigation completed properly," said County Sheriff Adan Mendoza. "And we want to release the proper information."

A family statement released by Hackman's daughters and granddaughter said the family would "miss him sorely."

"It is with great sadness that we announce the passing of our father, Gene Hackman and his wife, Betsy. 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," the statement read.

The actor is likely to be honoured at this year's Academy Awards, which take place on Sunday, March 2.