MISSION VIEJO – A mixed martial arts fighter was found naked inside a church after deputies responded to a reported break-in, authorities said.

“When (deputies) asked him his name he responded, ‘Mayhem,’ ” said Jim Amormino, spokesman for the Orange County Sheriff’s Department.

The man was identified by deputies as Jason “Mayhem” Miller, a mixed martial arts fighter who has fought in the UFC and was the host of MTV’s “Bully Beatdown.” He trained at the Reign Training Center in Lake Forest.

The professional fighter was spotted nude in Mission Hills Church, 24162 Alicia Parkway, on Monday morning when a pastor found several books and CDs on the first floor of the church, Amormino said.

Church officials boarded a broken window Saturday night, but the pastor found the board had been removed Monday morning, Amormino said. When the pastor went inside, he found the books and CDs scattered on the floor, as well as the residue of a fire extinguisher that had been sprayed throughout the first floor.

Deputies were called to the church at about 9 a.m. and searched the building. They found more powder that had been left behind by a fire extinguisher on the second floor.

Miller was then found on a couch without any clothes, he said.

Miller, 31, was coherent and answering deputies, Amormino said.

He was taken to Men’s Central Jail and booked on suspicion of burglary. He is undergoing a medical evaluation, Amormino said.

Contact the writer: shernandez@ocregister.com or 949-454-7361