New Delhi, Aug 13 (IANS): The process of acquiring VVIP choppers for the Indian Air Force IAF) deviated from the laid down procedures and caused delays, a Comptroller and Auditor General (CAG) report said Tuesday.

The CAG report, tabled in parliament, said as the acquisition was delayed the IAF continued to face operations disadvantage on account of use of ageing helicopters.

"The benchmarked cost adopted by the contract negotiating committee was unreasonably high compared to the offer cost," it said.

The Central Bureau of Investigation is looking into alleged kickbacks in the $750 million (Rs.3,600 crore) deal for 12 AgustaWestland AW101 helicopters for the IAF's elite Communication Squadron, which ferries the president, prime minister and other VVIPs.

A case has also been registered against former IAF chief Air Chief Marshal S.P. Tyagi.

The scam came to light when the Italian government arrested chopper maker Finmeccanica's CEO Giuseppe Orsi in February for allegedly paying bribes to clinch the deal.