Grand jury eyes monitor shutdown at Massey mine: report

CHICAGO (Reuters) - A federal grand jury looking into an explosion that killed 29 workers at a Massey Energy Co coal mine in West Virginia heard testimony this week about possible illegal tampering with a mine safety monitor, the Wall Street Journal reported on Saturday.

The testimony addressed an incident in which an electrician allegedly disabled a methane monitor at the Upper Big Branch Mine, according to the report quoting people familiar with the matter.

A former Massey worker who filed a whistle-blower lawsuit against the company reportedly witnessed the rewiring of a mining machine's methane monitor, the article said citing his lawyer. If functional, the monitor would shut down the machine if there was a dangerous buildup of gases.

Massey CEO Don Blankenship said this week that initial findings were that the April 5 blast was caused by methane gas.

Shane Harvey, Massey's general counsel, said the machine in question was not being used at the time to produce coal and that the company was cooperating fully with the criminal investigation, the report said.

The article also stated that federal prosecutors were reviewing a previously undisclosed investigation launched as early as 2008 about other safety problems related to the ventilation system at the mine. Harvey said he was unaware of any investigation in 2008, it said.

A company spokesperson did not immediately respond to a request for comment.

(Reporting by Michael Hirtzer; Editing by Eric Beech)