The founder and former chief executive of a major energy firm was killed in a traffic accident the day after he was charged with conspiring to suppress prices.

Aubrey McClendon, an Oklahoma wildcatter who bought up gas fields across the United States, crashed into an embankment while traveling at a “high rate of speed” in Oklahoma City.

Capt Paco Balderrama of the Oklahoma City Police Department told CBS that Mr McClendon's vehicle was engulfed in flames and so badly burnt that police could not tell if he was wearing a seatbelt.

“He pretty much drove straight into the wall,” he said.

The incident came a day the Department of Justice charged the part owner of the Oklahoma City Thunder basketball team with conspiring to suppress prices paid for oil and natural gas leases.

The indictment said that Mr McClendon, who led Chesapeake Energy before he was forced to step down three years ago, orchestrated a conspiracy in which two oil and gas companies colluded not to bid against each other for the purchase of several leases in northwestern Oklahoma.

According to the Justice Department, the companies decided who would win the leases, with the winning bidder allotting an interest in the leases to the other company.

“McClendon instructed his subordinates to execute the conspiratorial agreement, which included, among other things, withdrawing bids for certain leases and agreeing on the allocation of interests in the leases between the conspiring companies,” the department said in a statement.

Police said there was no other vehicle involved in the accident. They said they were still trying to determine the cause of the incident.