CHARLESTON, W.Va. -- Federal prosecutors say their investigation of the Upper Big Branch Mine Disaster has entered a vital phase, with new information giving them key leads toward more potential criminal charges.
Assistant U.S. Attorney Steve Ruby revealed the information in a new court filing that seeks to delay certain proceedings in a civil case by former Massey Energy shareholders who say they were deliberately misled about the company's safety record before the April 2010 explosion that killed 29 miners.
"The United States' criminal investigation of circumstances relating to the Upper Big Branch Mine is in a critical period, developing valuable information that became available only recently," the court filing said.
The government revealed no additional details in a court document filed as part of efforts to resolve a dispute over whether lawyers for the former Massey shareholders can conduct legal discovery -- obtaining documents and conducting interviews -- without jeopardizing the criminal probe.
Prosecutors and the former Massey company and executives agreed to ask U.S. District Judge Irene Berger to delay discovery in the shareholder case until January, the same deadline set in a similar case in Delaware business court.
In the court filing, the government said the delay would "allow the United States to pursue those leads and make decisions on potential charges without interference from civil discovery."
Prosecutors said that allowing discovery would give defendants in the civil case -- including most former top Massey executives -- access to documents they don't currently have about the company's operations at Upper Big Branch. Some of those defendants "may be or may become subjects of the criminal investigation," the government said, and access to such records would "allow them to anticipate in detail the direction of the criminal investigation."
"Civil discovery also would allow the civil parties to shape the record extensively for their own ends, making the United States' investigation -- and possible prosecutions -- more difficult," the court filing said.
Prosecutors also said that "even limited civil discovery" in the case would divert time and effort from the criminal investigation.
Lawyers for the former Massey shareholders argue that the government and the defendants are seeking too strict of a delay, and that they should be allowed to move forward sooner in some discovery activities.