BECKLEY, W.Va. -- A former Massey Energy official who is cooperating with prosecutors on Thursday implicated the company's former chief executive officer, Don Blankenship, in a decade-long conspiracy to hide safety violations from federal inspectors.

Former Massey official David C. Hughart pleaded guilty to two federal criminal charges that he plotted with other company officials to routinely violate safety standards and then cover up the resulting workplace hazards.

But a fairly routine plea hearing here took a surprising twist when U.S. District Judge Irene Berger pressed Hughart to name his co-conspirators and Hughart responded, "the chief executive officer."

Hughart did not use Blankenship's name, but Blankenship was CEO of Massey from 2000 until 2010, during the period when the crimes Hughart admitted to committing occurred.

In a nearly three-year investigation that started with the deaths of 29 miners in the Upper Big Branch Mine Disaster and has so far prompted four convictions, the accusation by Hughart is the first courtroom statement to specifically allege any wrongdoing by Blankenship.

William Taylor, a lawyer for Blankenship, said his client has done nothing wrong and downplayed the significance of what Hughart said.

"We were quite surprised at the reports of Mr. Hughart's statements at the time of his guilty plea," Taylor said. "Don Blankenship did not conspire with anybody to do anything illegal or improper. To the contrary, he did everything he could to make Massey's mines safe.

"We're not concerned particularly about the story concerning Mr. Hughart," Taylor said. "It's not surprising that people say untrue things when they are trying to reduce a possible prison sentence."

When he's sentenced on June 25, Hughart, 54, of Crab Orchard, faces up to six years in prison and a fine of up to $350,000. In a deal with prosecutors, Hughart pleaded guilty to one felony count of conspiracy to defraud the government by thwarting U.S. Mine Safety and Health Administration inspections and one misdemeanor count of conspiracy to violate MSHA safety standards. Hughart also agreed to cooperate with authorities in the ongoing criminal investigation of the mine disaster and broader questions about Massey safety practices.

"Guilty of both charges," Hughart told Berger when the judge asked him to enter his formal plea.

Hughart did not work at Upper Big Branch, and his plea deal involved crimes he has admitted committing between 2000 and 2010 at Massey's White Buck operations in Nicholas County, where two mid-level foremen and a Massey operating subsidiary were prosecuted five years ago for criminal safety violations.

Prosecutors identified Hughart as having served as president of Massey's Green Valley "resource group," which included White Buck. But Hughart also worked for Massey for more than 20 years, serving as an officer or a director at more than two-dozen subsidiaries, according to public records.

Hughart was fired in March 2010, and internal Massey records, filed in a circuit court case, allege he had failed a random drug test and received kickbacks from a Massey contractor.

In court documents in Hughart's case, prosecutors alleged a broader conspiracy by unnamed "directors, officers, and agents" of Massey operating companies to put coal production ahead of worker safety and health at "other coal mines owned by Massey." Those documents, filed in late November, were the first time in their Upper Big Branch probe that prosecutors have formally alleged Massey officials engaged in a scheme that went beyond the Raleigh County mine that exploded on April 5, 2010, and killed 29 workers.

Prosecutors allege that mine safety and health laws were routinely violated at the White Buck mines and other Massey operations, in part because of "a belief that consistently following those laws would decrease coal production."

Among the safety standards violated, prosecutors said, were those governing mine ventilation and control of explosive coal dust.

Investigators have said those standards were repeatedly ignored at Upper Big Branch, setting the stage there for a small methane ignition to turn into a huge, coal dust-fueled explosion.

And MSHA investigators have cited a Massey practice of providing "advance notice" of government inspections as a key factor in the mine disaster. MSHA investigators said this practice allowed Massey to fix hazards prior to inspections, but avoid more long-term safety improvements or tougher enforcement actions that might have prompted the mine to be closed.

During Thursday's plea hearing, Berger was running through a routine list of questions intended to assure that Hughart understood the charges against him and that he really committed the crimes he was admitting.

The judge pushed Hughart, asking him to explain exactly what "higher ups" he had worked with to provide advance notice of MSHA inspections. Hughart responded, "the chief executive officer." He did not mention Blankenship by name, and did not name any other Massey officials.

The hearing moved on, until Assistant U.S. Attorney Steve Ruby interrupted to tell the judge he believed Hughart may have misunderstood one of her questions. Ruby asked that the parties discuss that question with the judge in a private meeting at the bench, saying that the issue involved the government's ongoing criminal investigation. The judge agreed, and turned on a courtroom "white noise" system so spectators and the media could not hear the discussion. Later, both Ruby and Hughart's defense lawyer, Michael Whitt, refused to comment on what was discussed.

After the hearing, in an impromptu news conference just outside the courthouse, Hughart's wife and son both said Hughart was a good man who was just doing what Blankenship had ordered him to do.

"Don Blankenship is the reason we're here today," said Hughart's wife, Karen. "My husband was told he would be blackballed from the coal industry if he didn't go along."

So far, three individuals have been sentenced to jail in the government's criminal probe of the Upper Big Branch disaster and Massey Energy's safety practices.

A former Upper Big Branch miner, Thomas Harrah, was sentenced to 10 months in jail after he admitted to faking a foreman's license when he performed key mine safety examinations at the mine between January 2008 and August 2009, and then lied to investigators about his actions.

Berger sentenced a former Upper Big Branch security director, Hughie Elbert Stover, to 36 months in jail after Stover was convicted of two felonies: making a false statement and obstructing the government probe of the mine disaster.

And in January, the judge sentenced former Upper Big Branch superintendent Gary May to 21 months in jail and a $20,000 fine after he pleaded guilty to plotting to skirt safety rules and cover up the resulting hazards.

U.S. Attorney Booth Goodwin also reached a deal not to prosecute Alpha Natural Resources for any Upper Big Branch criminal liabilities it inherited when it purchased Massey Energy in June 2011. That deal required the firm to spend $80 million during the next two years on mine safety improvements and create a $48 million mine safety research trust fund. Alpha also agreed to pay $46.5 million in restitution to families of the disaster victims and $35 million to resolve pending Massey safety fines, including $10.8 million levied for violations related to the Upper Big Branch explosion.

Following previous developments in the case, Goodwin has said his investigation is continuing, and indicated that his team is following leads in an effort to move up the corporate ladder at Massey.

On Thursday, Goodwin's office issued a press release that didn't mention Hughart's statement about Blankenship, but touted the conviction of Hughart.

"Mine safety and health laws are not optional," Goodwin said in the release. "This prosecution reiterates the message that mine safety violations are very serious crimes."

Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.