A 79-year-old man being held in an Eagle River prison died Tuesday of apparently natural causes, state officials said Wednesday.

Warren Tanner was pronounced dead at 3:20 p.m. Tuesday at the Hiland Mountain Correctional Center, according to a statement from the state Department of Corrections.

DOC spokeswoman Megan Edge said a final cause of death would be determined by autopsy, but there were no signs of foul play.

“Suicide had nothing to do with Mr. Tanner’s passing,” Edge said. “We believe he suffered medical issues that led to his death.”

The Fairbanks Daily News-Miner reported that Tanner, a former commander of Alaska State Troopers' Fairbanks detachment, was convicted two years ago of sexually abusing a minor for inappropriately touching a girl when she was 3 to 4 years old. The abuse, which continued for nine years, wasn't discovered until the victim was 14.

Tanner had in custody with DOC since April 7, 2015. He had previously been held at the Goose Creek Correctional Center to serve his sentence, but was transferred to Hiland Mountain on May 1 of this year.

Edge said Tanner was part of a segregated group of male medium-security inmates being held at Hiland, primarily a women’s prison, as part of the faith-based TLC program which was moved there from Palmer.

“When the Palmer Correctional Center shut down it was doing really well, and they wanted to continue that work,” Edge said.

Tanner’s next of kin have been notified, and his death is being investigated by Alaska State Troopers as well as DOC’s Professional Conduct Unit. He is the eighth Alaska inmate to die this year.