Rolls-Royce shares tumbled on Thursday after it revealed that it had handed information to the SFO about claims of malpractice in Indonesia and China.
It is understood that Rolls-Royce uncovered the issues after an internal probe into the content of online posts made by a retired employee, Dick Taylor.
However, the SFO is not thought to be in contact with Taylor over his allegations, made over the course of several years in the comments sections of various news websites.
He has accused the firm of making a payment of around $20m to Tommy Suharto, the youngest son of former Indonesian President Suharto. Tommy was jailed in 2002 for ordering the murder of a judge.
Taylor, a former technical liaison manager for the firm, claims that the payment to Tommy Suharto was linked to a deal for airline Garuda to buy engines from Rolls.
The company declined to comment on the allegations yesterday, while the SFO did not return calls for comment.
Chief executive John Rishton said last week, after the firm reported its findings to the SFO, that Rolls “will take all necessary action to ensure compliance”.