BP is being investigated by US authorities over claims from a whistleblower that the oil company broke the law by not keeping key documents relating to a giant deepwater production platform in the Gulf of Mexico...The documents for the huge Atlantis platform act as an "operator's manual", and a complete up-to-date set of records is vital to shut down the platform properly in case of an emergency...The Minerals Management Service (MMS), the US government agency responsible for overseeing offshore oil and renewable activities, is expected to launch an investigation into the [Deepwater Horizon] disaster this week. But...a separate MMS investigation into the Atlantis rig allegations is being launched.