The US government sued offshore drilling group Transocean for blocking an investigation into the cause of the giant 2010 oil disaster off the coast of Louisiana.
The civil suit filed in Houston, Texas accuses the Swiss firm of failing to comply with five subpoenas issued by the Chemical Safety and Hazard Investigation Board (CSB), a government agency.
“Transocean’s ongoing failure to provide information has impeded and delayed the CSB’s critical safety inquiry,” Donald Holmstrom, director of CSB’s western regional office, said in an affidavit.
“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.”
The CSB also seeks information from Transocean to determine what role human factors may have played in the events leading up to the blowout and explosion.
The investigation is one of several being conducted by various government agencies and the lawsuit was filed the same day as regulators slapped Transocean, BP and Halliburton with citations that are expected to lead to massive fines.
The US Justice Department is also conducting a criminal investigation into the deadly disaster which killed 11 workers aboard Transocean’s Deepwater Horizon drilling rig on April 20, 2010.
By the time the well was capped 87 days later, 4.9 million barrels (206 million gallons) of oil had gushed out of the runaway well 5,000 feet (1,500 meters) below the surface of the Gulf of Mexico.
A key US government report released in September spread the blame for the massive oil spill, citing a bad cement job, poor management by BP and its subcontractors and risky shortcuts.
In a July 13 letter to the safety board provided to AFP on Wednesday, Transocean argued that the subpoenas were “improper” because the agency “lacks the authority and jurisdiction to investigate the Macondo incident.”
It noted that it had made “repeated voluntary efforts to satisfy the many queries and demands of CSB” and had also cooperated with “a number of federal investigations.”