NEW DELHI: Former Indian Air Force (IAF) chief S.P. Tyagi was on Friday arrested by the CBI  on charges of corruption in the Rs 3,600 crore AgustaWestland VVIP choppers deal.

Tyagi, who retired in 2007, was questioned by the CBI extensively in the past in this case. Along with Tyagi, his cousin Sanjiv alias Julie Tyagi and lawyer Gautam Khaitan were also arrested.

71-year old Tyagi, who retired in 2007, was called for questioning at CBI Headquarters along with his cousin and Chandigarh-based lawyer Gautam Khaitan, who were taken into custody after nearly four hours of grilling, CBI sources said.

These are the first arrests in the case by CBI which came three years after it registered an FIR in 2013 to probe the allegations in the aftermath of the details of the scam emerging in Italy where the prosecutors levelled allegations of corruption in the deal against the chief of Finmeccanica, the parent company of AgustaWestland.

In a statement in the evening, CBI spokesperson Devpreet Singh said, "It was alleged that Chief of Air Staff (CAS) entered into criminal conspiracy with other accused persons and in 2005, conceded to change IAF's consistent stand that service ceiling of VVIP Helicopters 6000 mtrs was an inescapable operational necessity and reduced the same to 4500 meters."

She said such changes in Operational Requirements (ORs) made the private company based at the UK (AgustaWestland), eligble to participate in the Request for Proposal for VVIP Helicopters.

"It was revealed during investigation that such undue favours were allegedly shown to said UK-based private company by accepting illegal gratification from the accused vendors through middlemen/relatives including his cousin and an advocate etc. who accepted the illegal gratification for exercising influence through illegal means, or using personal influence over the concerned public servants," CBI Spokepserson said.

Singh said the arrested accused persons will be produced before the competent court tomorrow where their remand would be sought.

In media interviews during the last three years, Tyagi and his cousin had strongly denied having taken any bribes to influence the deal.

Rejecting the allegations, Air Chief Marshal Tyagi had said the change of specifications, which brought AgustaWestland into contention, was a collective decision in which senior officers of Indian Air Force, SPG and other departments were involved.

CBI had claimed that Khaitan accepted having taken money from European middlemen Guido Haschke and Carlo Gerosa but insisted it was not kickbacks to influence the deal.

and evidences in this case.