A newspaper says it has obtained an internal audit conducted by BP PLC on the Deepwater Horizon oil rig that details severe safety flaws months before the Gulf of Mexico spill.
The Sunday Times said in its report that the audit details how the drilling rig, owned by contractor Transocean, did not fully comply with BP's standards.
The report says that seven months ahead of the April explosion, auditors found 390 maintenance tasks that were more than a month overdue on the rig. These included maintenance work on parts of the blowout preventer, the safety device atop the well that failed to trigger on the day of the accident.
BP and Transocean, which could both face heavy penalties, have disagreed on who should take responsibility for the spill.
For government lawyers preparing a case against BP, this number could help calculate the maximum civil penalty BP might face for the spill. If BP is not found to have acted with negligence, the penalty would be $1,100 per barrel. About 4.1 million barrels escaped into the gulf, according to the new estimate, so that fine would come to $4.5 billion. If BP is found to have acted with "gross negligence" in the lead-up to the spill, the maximum penalty would be $4,300 a barrel, which would work out to $17.6 billion.