Aerospace and defense group Rolls-Royce said Monday that the UK's Serious Fraud Office (SFO) had launched a formal investigation into concerns raised a year ago of possible bribery and corruption in China and Indonesia.

Rolls Royce said in December 2012 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.

"We have been informed by the Serious Fraud Office that it has now commenced a formal investigation into these matters," Rolls-Royce said Monday.

"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.

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.

Rolls-Royce said in January that lawyer David Gold, a Conservative life peer, would lead a review of its compliance procedures after the allegations emerged.

Allegations of corruption are not new to the defense and aerospace industry, in which companies commonly use individuals or companies as intermediaries in countries where they do not have a large presence.