The Deepwater Horizon oil rig in the Gulf of Mexico burst into flames April 20, leaving several workers injured and 11 dead.
Jordan Barab, deputy assistant secretary of labor for the Occupational Safety and Health Agency, told the Financial Times that the British energy company had a "systemic safety problem."
"BP executives, they talk a good line. They say they want to improve safety," said Barab. "But it doesn't always translate, unfortunately, down to the refineries themselves."
OSHA in October fined BP more than $87 million for violations of workplace safety regulation. The U.S. safety regulator fined the oil company $21 million in 2005 following an explosion at its refinery in Texas City, Texas, that killed 15 workers.
BP executives told the Financial Times that it is in "full compliance" with OSHA regulations, investing more than $1 billion to improve safety at the Texas City refinery.
Barab said it was evident in the wake of the Deepwater Horizon explosion that BP has not done enough to meet its safety obligations.
"This is obviously an important case for us," he said. "We're prepared to carry it to the end."