Betsy Arakawa, a classical musician and small-business owner who was married to Gene Hackman and helped edit his novels, died on Wednesday with him at their home in Santa Fe, N.M., the local authorities said on Thursday. She was 65.

Sheriff’s deputies found the bodies of Ms. Arakawa and Mr. Hackman, 95, along with one of their dogs, on Wednesday afternoon, according to a statement from the Santa Fe County Sheriff’s Department. The cause of death was unclear and under investigation.

Mr. Hackman was nominated for five Academy Awards and won two during a 40-year acting career. In his later years, he became a published author, witing three historical novels, and he attributed his writing style, in part, to Ms. Arakawa.

“If in fact I have a style, it came from repeated edits, friends’ suggestions and my wife’s unwavering, specific read-throughs,” he told the “Writer’s Bone” podcast in 2014.

Mr. Hackman would write his books with pen and paper, and Ms. Arakawa would type them up on a computer, making edits or sharing thoughts on characters with him, according to Barbara Lenihan, a friend of the couple for nearly 35 years.

“She was very involved with what he did,” Ms. Lenihan said. “She made it very possible for him to do it.”