SAN DIEGO — Mixed-martial-arts fighter “War Machine” was arrested Friday afternoon in Simi Valley on suspicion of brutally beating his ex-girlfriend in Las Vegas last week, the U.S. Marshals service said.

The fighter, whose birth name is Jonathan Koppenhaver, was taken into custody without incident at the Extended Stay America hotel in Simi Valley at about 2:30 p.m., a spokeswoman for the Marshal’s Service said.

Koppenhaver, who currently lives in San Diego, was a former resident of Simi Valley and investigators developed information that he had been staying there, according to the Simi Valley Police Department.

Koppenhaver was taken to the Ventura County Jail for booking on multiple warrants from Nevada.

Las Vegas Metro police said they responded to Mack’s home early on the morning of Aug. 8 due to a domestic dispute between ‘War Machine,’ Mack and an unnamed man.

Mack and the man suffered severe, but non-life threatening injuries in the fight,  reported. “War Machine” was not at the location when police arrived. Las Vegas police issued warrants for “War Machine’s” arrest alleging battery, strangulation, gross lewdness, assault with a deadly weapon and coercion/threat with force, according to MMAfighting.com.

Earlier this week, reality TV star Duane Chapman, known as Dog the Bounty Hunter, vowed to track down “War Machine.” On Thursday, Chapman showed up in San Diego, stopping by Undisputed Downtown San Diego, the gym where “War Machine” trains. He also went to “War Machine’s” San Diego apartment, but the MMA fighter was not there.