The Central Bureau of Investigation has registered a Preliminary Enquiry against unknown officials of the Ministry of Defence and others on a reference from the MoD on allegations related to Brazilian firm Embraer employing an agent to facilitate various contracts.

These include the contracts for Airborne Early Warning and Control project with Centre for Air Borne Systems / Defence Research of Development Organisation for procurement of three aircraft.

Earlier, the Defence Ministry had written to the CBI, seeking a probe into the allegations of kickbacks in the 2008 Embraer aircraft deal.

The deal was signed between Embraer and the Defence Research and Development Organisation for three aircraft equipped with indigenous radars for airborne early warning and control systems.

The $208-million (Rs 1,390 crore) jet deal with the Brazilian aircraft maker during the United Progressive Alliance regime kicked up dust with United States authorities going into alleged payment of kickbacks.