-- An attack on a Los Alamos nuclear lab auditor outside a strip club in Santa Fe, N.M., was unrelated to his status as a whistle-blower, authorities said Thursday, challenging his allegation that he was beaten to ensure his silence.

Tommy Hook, 52, suffered a broken jaw, a herniated disc and missing teeth in the attack outside the Cheeks nightclub in Santa Fe early Sunday. He has said the beating was carried out by thugs intent on keeping him from talking about alleged financial irregularities at the nuclear lab.

But police said the attack occurred after Hook's car hit a pedestrian while leaving the club.

"Facts, evidence and information obtained during the course of this investigation has led investigators to believe that the altercation involving Mr. Hook is an isolated incident and is in no way related to Mr. Hook's whistle-blower status at the Los Alamos National Laboratories," Santa Fe Deputy Police Chief Eric Johnson said in a statement.

The investigation is "leaning toward a fight in the parking lot as a result of Mr. Hook backing into a pedestrian," Johnson said. He said after Hook hit the pedestrian, he exited his vehicle, "at which time the confrontation escalated into a physical attack."

Police said they have identified people involved in the attack.

Hook did not return calls. A colleague, Chuck Montano, said Hook stands by his version the attack.