Image copyright AFP

A US mixed-martial arts combatant known as War Machine has been jailed for life for kidnapping, and sexually assaulting his former girlfriend in 2014.

Jonathan Paul Koppenhaver was found guilty in March of attacking Christy Mack and her friend Corey Thomas after accusing them of having an affair.

Ms Mack suffered a fractured eye socket and nose, broken ribs and lost teeth.

In a statement to the court Koppenhaver expressed remorse, attributing the attack to anxiety and depression.

He compared himself to former NFL star Aaron Hernandez, who killed himself in prison earlier this year while serving a life sentence for murder.

Image copyright Christy Mack Image caption Christy Mack posted her account of the i2014 incident on Twitter, along with graphic photos of herself in hospital

"Not a day goes by that I don't seriously regret all those things that I did. I was a very, very lost, very empty person," Koppenhaver told the Las Vegas court.

"And to top it off, something's not right with my head. Plain and simple."

His comments are in contrast to comments made on Twitter in March, when he said he was unfazed at the possibility of receiving "some type of life sentence".

Adult actress details alleged assault on Twitter

Ms Mack met Koppenhaver in 2013 when she was a well-known porn actress. Koppenhaver had also worked occasionally in the industry. But their relationship soon deteriorated, with Ms Mack accusing the wrestler of becoming abusive.

Ms Mack - who also suffered liver and leg injuries in the assault - told the court that she will be in fear for her life if Koppenhaver is allowed to leave prison.

"I do know when he gets out, he will kill me," she said.

Koppenhaver, 35, will only be considered for parole after 36 years in jail. The wrestler won 14 of his 19 mixed martial arts fights.

He was convicted on 29 counts including kidnap and attempted rape. The jury was unable to agree on two counts of attempted murder.