A Massey Energy Co. security chief was convicted Wednesday on both charges he was facing related to the investigation of the 2010 explosion in West Virginia that killed 29 miners.

Hughie Elbert Stover was found guilty by a jury in U.S. District Court in Beckley, W.Va., of obstructing a federal criminal investigation, and lying to federal investigators. Stover, who had been security chief of the Upper Big Branch mine since 1999, faces a maximum penalty of 25 years in prison but remains free pending a Feb. 29 sentencing.

No other mine personnel or Massey officials have been charged but the criminal investigation is continuing.

The obstruction charge was for ordering a security guard to dispose of thousands of security-related documents earlier this year, several months after Mr. Stover was interviewed by investigators about the accident.

Stover testified Tuesday in his own defense that the records disposal was an innocent oversight, the "stupidest mistake" he had made in his life.

He was charged with lying to federal investigators about notifying mine personnel when government inspectors arrived on the property, which is itself a violation of federal law. He testified that he hadn't lied to investigators about announcing government inspectors because he understood notification to involve using the telephone, a practice he prohibited.