Updated

A former president of a Massey Energy subsidiary has implicated the coal company's ex-CEO in safety violations as he pleaded guilty to charges resulting from an investigation into the 2010 explosion at a Massey mine that killed 29 men.

David Hughart entered the plea to two federal conspiracy charges on Thursday in federal court in Beckley. He was accused of working with others to ensure miners at Massey operations got advance warning about surprise federal inspections.

When asked by the judge where the orders for the advanced warning came from, Hughart said it came from the company's chief executive officer. The CEO at the time, Don Blankenship, was not mentioned by name, and federal prosecutors declined comment after the hearing.