“It goes without saying that government officials have to follow the law like everyone else and if we get leads that raise questions about whether they have, we investigate,” US attorney for the Southern District of West Virginia Booth Goodwin told ILN on Monday morning.

“I can’t comment on the status of specific leads but we obviously pay close attention to what a defendant says at a plea hearing.”

May’s testimony was taken about two weeks ago on March 29, when 43-year-old May entered a plea deal with federal officials for his cooperation with the criminal investigation into the April 2010 explosion at the Raleigh County mine that killed 29 miners.

The statement regarding the possible tip-offs came during a line of questioning from US District Judge Irene Berger.

According to media reports, Berger asked May who else played a role in the conspiracy to hide safety violations by working with others to provide advance notice that an inspector was onsite at the mine.

“It started, you know, from the MSHA inspectors coming on the property,” May reportedly testified under oath, according to the Associated Press.

“Sometimes they would tell us, you know, they'd be back tomorrow or where they were going.

“And it went from there to telling everybody that was outside, you know, just scatter word by mouth on the phone and they would tell whoever was underground.”

He also told Berger the practice by federal inspectors occurred for his entire tenure at UBB, as well as every mine he had ever been to.

When pressed further by the district judge as to whether he intended to indicate that MSHA inspectors were part of the greater conspiracy, May denied that intent.

“I don't believe it's a conspiracy but I think, in my opinion, if they would let me know that … I would let everyone else know that,” he reportedly responded.

Federal regulations under the Mine Safety and Health Act prohibit the advance notice of inspections by anyone, be it mine employees to others or on the part of its own federal inspectors.

The violation carries a fine of $US1000 as well as a six-month jail sentence.

Goodwin did not provide further comment, including the progress of any probe into the agency’s actions.

An ILN request for comment and information from an MSHA spokesperson was not immediately returned.

May’s sentencing is scheduled for August 9.

Meanwhile, former UBB security chief Hughie Elbert Stover filed an appeal to his conviction and three-year sentence handed down earlier this year for lying to federal investigators and ordering the destruction of documents related to the events at the mine.

Owner Alpha Natural Resources acquired the UBB mine along with its takeover of Massey Energy last June and last week announced it would permanently close the mine later this year.