Horrifying moment man got torn apart by jealous chimpanzees after he delivered cake to his former chimp pet

A 62-year-old man was left in critical condition after his attempt to treat his former pet turned into a viscous attack.

St James Davis became the owner of a chimpanzee named Moe in the 1960s, and enjoyed his company for 30 years before being forced to give him up.

Moe was taken away from Davis and his wife in 1999, after Moe injured a woman's hand and she took them to court.

Moe lived with St. James and LaDonna for 30 years (Myung J. Chun/Los Angeles Times via Getty Images)

Despite the fact Moe no longer lived with Davis, the owner didn't forget about his former pet and in 2005 went to visit him at the Animal Haven Ranch near Bakersfield, California.

Davis wanted to deliver a birthday cake to Moe, but things turned disastrous when Davis caught the attention of two male chimpanzees, 16-year-old Buddy and 13-year-old Ollie, which were housed in a cage next to Moe.

Steve Martarano, a spokesperson for the California Department of Fish and Game, spoke about the incident to AFP, saying: "The Davises were visiting Moe to give him a birthday cake, and somehow the two males escaped from the cage next to Moe's that housed a total of four chimpanzees.

"Moe was not involved in the attack."

St James and LaDonna had been delivering cake to Moe when the chimps attacked. (Myung J. Chun/Los Angeles Times via Getty Images)

After the two males escaped, they proceeded to attack Davis and cause 'substantial injuries to his face, abdomen and upper body', Martarano said.

Part of Davis' face was actually torn off in the encounter, with Martarano adding: "It was a very bloody attack indeed."

Davis had to be rushed to hospital in the wake of the incident, where he received reconstructive surgery to reattach parts of his face which had been torn off by the chimps.

One of his feet and his testicles were also mauled, and his wife, LaDonna, suffered serious hand injuries.

The attack came to an end when Buddy and Ollie were shot dead by a relative of the person who owned the animal sanctuary.

In the aftermath of the attack, chimpanzee experts expressed belief that it may have been prompted by jealousy, or a mistaken threat.

St James was left permanently disfigured in the attack (YouTube/The Enigma)

Martine Collette, of the Wildlife Waystation, suggested the attack could have come about after a human 'did something that in the mind of a chimpanzee is perceived to be an insult or a slight', ABC News reports.

She added that jealousy could be a factor, saying: "There are chimps who are shy, some who are very aggressive, some who are good natured. But it's circumstances that set chimps off."

While the two male chimps were attacking Davis, two female chimps held in the same cage also managed to escape. They were later caught and returned to their enclosure.

Davis was left permanently disfigured as a result of the incident, but the tragedy only continued when Moe disappeared after escaping from his own cage in 2008.

He's never been found, but Davis said after his disappearance that he had 'never loved anything as much as [he] loved Moe'.