The Pilatus PC-7 Mk-II is a Swiss-made basic trainer aircraft

Highlights CBI alleged kickbacks up to Rs 339 crore were paid in a deal

Irregularities in procuring 75 trainer aircraft in 2009 were also alleged

CBI also raided properties owned by arms dealer Sanjay Bhandari

The Central Bureau of Investigation has filed a case against unknown officials of the Air Force, the Defence Ministry, arms dealer Sanjay Bhandari and officials of Swiss-based plane-maker Pilatus Aircraft Ltd over alleged irregularities in procurement of 75 basic trainer aircraft in 2009. The CBI alleged kickbacks up to Rs 339 crore were paid in the deal.

The CBI raided properties owned by Mr Bhandari and other accused in and around Delhi on Friday. Officials said raids are continuing in more places.

In its First Information Report (FIR), the CBI also named Offset India Solutions Pvt Ltd, a company owned by the arms dealer at south Delhi's Panchsheel Park.

The scope of the investigation into the activities of Mr Bhandari first widened in June 2016 to involve India's acquisition of the Swiss-made basic trainer aircraft (BTA).

Mr Bhandari is already being investigated for allegedly buying a benami or proxy-owned house for businessman Robert Vadra in London. Investigators have also been probing what kind of services his company, Offset India Solutions Pvt Ltd, had provided to the Swiss aircraft firm.

Trainer aircraft are the planes used to teach cadets to fly when they join the air force. The Air Force had decided to purchase the Pilatus PC-7 Mk-II after the indigenous HTP-32 was grounded due to repeated failures.

When the Manmohan Singh government had signed a Rs 2,896 crore deal for 75 BTA with Pilatus Aircraft in May 2012, the competitors had red flagged the purchase.