BECKLEY, W.Va.—A former Massey Energy official who is cooperating in the investigation of the Upper Big Branch mine disaster is asking a judge for leniency when he's sentenced Aug. 1.

Defense attorneys tell U.S. District Judge Irene Berger that David Hughart's life has been ruined because he's been unfairly linked to the 2010 explosion that killed 29 men.

Hughart pleaded guilty to conspiracy charges, admitting he helped give miners at another Massey subsidiary advance warning about surprise inspections.

At his plea hearing in February, Hughart implicated former chief executive Don Blankenship in the scheme. Massey is now owned by Virginia-based Alpha Natural Resources.

Hughart faces up to six years in prison when he is sentenced.

Assistant U.S. Attorney Steve Ruby says lives were endangered and Berger should consider a stiffer sentence.