British aircraft engine maker Rolls-Royce revealed Thursday that it is facing a corruption probe in the United States as well as Britain.

"The group is currently under investigation by law enforcement agencies, primarily the Serious Fraud Office (SFO) in the UK and the US Department of Justice (DoJ)," the company said in its annual report.

"Breaches of laws and regulations in this area can lead to fines, penalties, criminal prosecution, commercial litigation and restrictions on future business."

Rolls-Royce had revealed late last year that Britain's SFO had launched a formal investigation into alleged bribery linked to the group's overseas operations.

The company had warned in 2012 that it might be prosecuted over alleged "malpractice" in Indonesia and China after passing on information related to bribery concerns to the office.

The London-listed firm stressed on Thursday that it was cooperating with the investigations but has yet to receive official notice of a formal DoJ probe.

"Rolls-Royce has been cooperating with regulatory authorities on both sides of the Atlantic in regard to allegations of bribery and corruption," it added.

"The SFO in the UK has launched a formal investigation. The DoJ is also investigating these matters, however we have received no notification of a formal enquiry being launched in the United States."

Earlier this week, meanwhile, India's defence ministry ordered an investigation into the purchase of jet fighter engines from Rolls-Royce in a deal reportedly worth $1.6 billion, an official said on Monday.

The Central Bureau of Investigation (CBI) will probe allegations of kickbacks over the deal for Rolls-Royce to supply engines to state-run Hindustan Aeronautics Ltd (HAL) between 2007 and 2011, a defence ministry official had told AFP.