The Department of Justice yesterday filed a civil lawsuit against the owner of the Deepwater Horizon rig that exploded last April in the Gulf of Mexico for an alleged failure to cooperate with an ongoing federal investigation.

The lawsuit alleges that Transocean Ltd. has ignored subpoenas issued by the U.S. Chemical Safety and Hazard Investigation Board (CSB). The complaint alleges that Transocean has failed to sufficiently respond to 38 of 39 specific demands contained in five CSB subpoenas issued between Nov. 24, 2010, and April 7, 2011.

U.S. attorney Kenneth Magidson filed the lawsuit yesterday in Houston, Texas.

Donald Holmstrom, one of CSB's investigators, said in an affidavit that the lack of cooperation from Transocean is hampering the agency's ability to finish their investigation.

"Transocean's ongoing failure to provide information has impeded and delayed the CSB's critical safety inquiry," Holmstrom wrote. "Transocean's production of information in compliance with these subpoenas is required to evaluate Transocean's internal safety culture, managerial decision making and incident response mechanisms."

CSB conducts investigations into chemical facility incidents where deaths or human injury occur. Their reports, which typically take 18 to 24 months to complete, are typically among the most extensive of any federal agencies.

This is not the first time CSB has criticized Transocean. Last month, CSB Chairman Rafael Moure-Eraso told Greenwire that the rig owner has been unusually uncooperative with CSB's investigation, which was requested by Congress (Greenwire, Sept. 29).

Transocean strongly denied the CSB charges. It has also, however, called into question what jurisdiction CSB has for requiring Transocean to turn over information.

"In fact, the company's cooperation with the CSB has gone above and beyond the limits of the agency's jurisdiction in the matter," Transocean spokesman Brian Kennedy said last month. "Any suggestion to the contrary is simply untrue."

Transocean also sent the Justice Department a letter in July that argued that the U.S. Coast Guard and Interior Department have jurisdiction to investigate offshore drilling spills, not CSB. It also said that much of the information requested by CSB has already been turned over by the company as part of other investigations and lawsuits.