Former air chief SP Tyagi and his cousins will be questioned by the CBI next week in the chopper scam. Armed with documents from Italy, the CBI on February 25, named the former Air Force chief in its preliminary enquiry into allegations of kickbacks in the Rs 3,600 crore VVIP chopper deal, the second former defence services chief to figure in a scam probe.

Besides the former IAF chief, 10 others including his cousins -- Julie, Docsa and Sandeep Tyagi have also been named along with four companies in the enquiry, CBI sources said.

The CBI has registered the preliminary enquiry to probe allegations that some "middlemen have influenced the deal in favour" of the Italian company AgustaWestland for the supply of 12 helicopters.