Mixed martial arts star known War Machine was found guilty on Monday of kidnapping, sexually assaulting and beating his porn star ex-girlfriend, and also attacking her male friend when he found them in bed together.

War Machine, who changed his name from Jonathan Koppenhaver, was found guilty on 29 of 34 charges – including domestic violence, sexual assault, kidnapping and coercing witnesses – in the attack on porn star Christy Mack and her friend Corey Thomas in August 2014.

The jury was deadlocked on the most serious charge – that of attempted murder.

Koppenhaver, 35, did not testify at the Las Vegas court on Monday, but his lawyers said he admitted assaulting the pair after storming into Mack's home and finding them together.

Jay Leiderman, Koppenhaver's lawyer, said brain injuries and a cocktail of drugs – including steroids – combined with rage and shock had resulted in a situation in which "someone loses their mind," CNN reported.

Prosecutors alleged there was no evidence that War Machine was on drugs at the time of the attack, and that Mack suffered physical abuse throughout her 15-month relationship with Koppenhaver.

Thomas testified that he suffered a broken nose, dislocated shoulder, scrapes, bruises and bite marks.

Mack, 25, whose real names is Christine Mackinday, told jurors that after attacking Thomas, Koppenhaver unleashed his anger on her, and left her with injuries including missing teeth, a broken eye socket, a fractured rib and a ruptured liver.

She said he also attempted to rape her at knife point and threatened to kill her and she ran bleeding to a neighbours when he went to the kitchen to get a knife.

She has waived her automatic right to anonymity as a victim of sexual violence.

Koppenhaver has been kept in jail until his sentencing, and faces a possible life sentence without the possibility of parole for the attacks.

His legal team said he intends to appeal the verdict.