New Delhi has reportedly ordered a probe into alleged irregularities over the supply of Rolls-Royce aero engines for India’s military over a period spanning four years from 2007 to 2011.

Widespread media reports in India say the probe was ordered by defence minister AK Antony, and will be conducted by the Central Bureau of Investigation (CBI).

R-R has yet to issue an official response to the reports. A spokeswoman told Flightglobal that the company "can't comment on an ongoing investigation."

Sources at Indian airframer Hindustan Aeronautics (HAL) have confirmed to Flightglobal that it had received allegations about the issue. After conducting internal investigations it decided to refer the matter to the defence ministry and CBI.

The 2007-2011 timeframe coincides with the license production of R-R Adour Mk 871 engines by HAL for the BAE Systems Hawk Mk 132 advanced jet trainers (AJT) in use by the Indian air force and navy. In 2010 R-R received an order worth £200 million ($335 million) to provide engines for an additional 57 Hawk AJTs purchased by New Delhi.

The aircraft were ordered in two batches of 66 and 57 aircraft. Of the total 123 Hawks, 106 will go to the air force and 17 to the navy. The first 24 aircraft were delivered directly by BAE Systems, while HAL produced the remaining 42 aircraft from the first tranche. Handovers of the jets from the second deal have since commenced.

An additional 20 Hawks were to have been ordered for the nation's Suryakiran display team, though this could now be delayed until the probe is completed. India is the largest operator of the Hawk AJT.

In a statement released on 23 December 2013 R-R confirmed that “further to our announcement of December 6th 2012 relating to concerns about bribery and corruption in overseas markets, we have been informed by the Serious Fraud Office that it has now commenced a formal investigation into these matters.”

If R-R were to become embroiled in legal issues in India, it could create problems for a number of programmes, including New Delhi’s planned acquisition of the Airbus A330 multi-role tanker transport (MRTT). One of the engine options is the R-R Trent 700, but India is set to select a powerplant for the aircraft.

Two other R-R engines, the AE 2100D2 and the AE 2100J are fitted on the Alenia Aermacchi C-27J Spartan and ShinMaywa US-2 amphibious aircraft. The Spartan is competing for a 56 aircraft requirement to replace the Indian air force's Avro HS-748 fleet, while the its navy is considering the US-2.

Among R-R’s more recent successes in India have been repeat orders for its AE 2100D3 engines on the Lockheed Martin C-130J - India has taken delivery of six aircraft with six more on order. The engine maker's AE 3007 engines power the Embraer Legacy 600 jets used for VVIP transport, and the EMB-145 airborne early warning and control (AEW&C) platform being developed by the Defence Research Development Organisation.