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In court on Saturday, Mr Tyagi, who headed the Air Force between 2005 and 2007, said that changing the specifications of the helicopters was not his decision alone. Mr Tyagi's lawyer said that in 2003 the Prime Minister's Office asked the air chief to get involved in the procurement. In a 2005 meeting, the changes in requirements were suggested, he said.
He has been accused by investigators in Italy and India of abusing his official position to swing the contract in favour of Finnmeccanica, the parent company of UK-based helicopter maker AgustaWestland, by tailoring specifications of the tender at the instance of his cousins.
While not sharing details, the CBI said the evidence against the former air chief warranted his arrest in the deal which was signed when Congress was in power. They wanted him in custody for 10 days.
"It was alleged that (the then) Chief of Air Staff entered into criminal conspiracy with other accused persons and in 2005, conceded to change IAF's consistent stand that service ceiling of VVIP Helicopters 6,000m was an inescapable operational necessity and reduced the same to 4,500m," CBI spokesperson Devpreet Singh said, adding that reducing the required flying height of the chopper made AgustaWestland eligible to participate in the Request for Proposal for VVIP helicopters.
Investigations have revealed that the Tyagis entered into a consultancy deal with middlemen in 2004, when Air Marshal Tyagi's cousins were certain that he would be the next air force chief and in a position to influence the deal.
Investigators say there is evidence that Air Mashal Tyagi met with a top official of Finmeccanica when he was Air Chief.
The Enforcement Directorate alleges that payments were made through Tunisia-registered companies controlled by Switzerland-based intermediaries Guido Haschke and Carlo Gerosa and transferred to accounts in India and Mauritius.
The contract to acquire 12 AgustaWestland 101 VVIP helicopters for the President, Prime Minister and other top leaders of the country was signed by the Congress government in 2010. Three helicopters had been delivered to India before the deal was stalled in 2013.
The CBI had registered a case against the former air chief and 18 others, including his cousins and European middlemen, three years ago.
Rakesh Asthana, who has ordered the arrest, has been in the headlines over his appointment as the acting CBI chief, with the opposition alleging that the government did not follow the rules for selection.
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