A former BP engineer in the US was arrested last night and charged with trying to destroy evidence relating to the scale of the Gulf of Mexico oil spill in April 2010.
Kurt Mix, 50, faces the first criminal charges to be laid over the spill, the largest in US history. Just how large is still unresolved, and the exact number of barrels of oil that escaped from the ruptured Macondo well is crucial for determining the size of fines that BP will have to pay under US clean water laws.
Mr Mix is accused of deleting hundreds of text messages between him and a supervisor that included "sensitive internal BP information", according to the Department of Justice.
The messages suggested that the so-called "top kill", an operation to plug the leak by pumping mud into the well, was failing to achieve results even while BP was publicly expressing optimism.
Mr Mix, a drilling and completions engineer for BP before he resigned this January, deleted the messages in October 2010 when he learned his electronic files were going to be collected by a vendor working for BP's lawyers, according to prosecutors.
BP had "sent numerous notices to Mix requiring him to retain all information concerning Macondo" before he allegedly deleted messages, the Justice Department said.