Oregon authorities are investigating how farmer Terry Vance Garner was devoured by his pigs in Coos County.

Terry Vance Garner, 69, went to feed his animals last Wednesday on his farm by the coast, but never returned.

His dentures and pieces of his body were found by a family member in the pig enclosure, but the rest of his remains had been consumed.

The Coos County district attorney’s office said that one of the animals had previously bitten Terry Vance Garner.

The animals are estimated by the authorities to each weigh about 700 lb (320kg).

Investigators say it is possible that the hogs knocked Terry Vance Garner over before killing and eating him.

But they have not ruled out the possibility that the farmer could have collapsed from a medical emergency, such as a heart attack.

A pathologist was unable to determine the cause of Terry Vance Garner’s death and his remains have been sent to the University of Oregon to be analyzed by a forensic anthropologist.

Terry Vance Garner’s older brother, Michael, described him as a “good-hearted guy”.

He said his brother had raised several large adult sows and a boar called Teddy, and they would sell their piglets to local children.

“Those animals were his life,” Michael Garner, 75, told the Register-Guard newspaper.

“He had all kinds of birds, and turkeys that ran all over the place. Everybody knew him.”

Terry Vance Garner was a Vietnam war veteran who suffered from post-traumatic stress disorder, according to his brother, and the farm had been a “life-saver” for him.

Michael Garner said one of the hogs had bitten his brother last year, after he had accidentally stepped on a piglet.

“He said he was going to kill it, but when I asked him about it later, he said he had changed his mind,” he told the Register-Guard.

Coos County District Attorney Paul Frasier told the local newspaper: “For all we know, it was a horrific accident, but it’s so doggone weird that we have to look at all possibilities.”

Paul Frasier added that he had not intended to release details about the case, but changed his mind after word spread about the incident.