Aerospace and defence group Rolls-Royce said Britain's Serious Fraud Office has launched a formal investigation into concerns raised a year ago of possible bribery and corruption in China and Indonesia.
Rolls-Royce, the world's second-largest maker of aircraft engines, said last December it had passed information to the SFO relating to bribery and corruption involving intermediaries in overseas markets.
Rolls-Royce said at the time that it could face prosecution over the allegations.
Shares in the company fell slightly.
"This is just the next step in the process," Liberum analyst Ben Bourne said of Rolls-Royce's announcement. The SFO has been reviewing the findings of Rolls-Royce's internal probe since earlier this year.
Tommy Suharto, the youngest son of Indonesia's late president, in November denied allegations that he received bribes from Rolls-Royce. A source said last December that the allegations related to the "distant past".
That suggests the offences would not fall under the British Bribery Act, which came into effect in July 2011. This tougher law introduced an offence of failure to prevent bribery, and clamps down on "facilitation payments" and disproportionate hospitality to oil the wheels of business.