Aubrey McClendon walks through the French Quarter in New Orleans, Louisiana March 26, 2012. REUTERS/Sean Gardner/Files

HOUSTON (Reuters) - Oklahoma City police said on Tuesday an inquiry found no evidence suggesting oilman Aubrey McClendon committed suicide when he died in a fiery crash in March, but acknowledged his state of mind at the time of the accident was unknowable.

McClendon’s Chevy Tahoe slammed into a concrete bridge abutment on March 2, one day after federal prosecutors indicted him for violating anti-trust laws by rigging bids for oil lands. He had denied the charges.

Details of the crash, in which his vehicle was driving well above the speed limit at 88 miles (142 km) per hour, stunned the U.S. energy industry. Many executives worried he had committed suicide.

“Our investigators found no information that would compel us to believe this was anything other than a car accident,” police Captain Paco Balderrama said.

“With 100 percent certainty we will never know what his state of mind was” at the time of the crash, he said.

The findings of the inquiry were first reported by the Wall Street Journal.

Investigators have previously said McClendon died of multiple blunt force trauma, though a final report from the medical examiner’s office is still pending.