Officials said Tyagi was subjected to the marathon questioning after a similar ten-hour session yesterday by Enforcement Directorate (ED) investigators.
Tyagi arrived at the zonal office of the agency and left after about eight hours as he was put through more questions and evidences collected in the case by the Investigating Officer (IO) of the case, they said.
Agency sources had yesterday said Tyagi was questioned about his role in the deal and his statement was recorded under the Prevention of Money Laundering Act (PMLA).
The retired Air Chief Marshal was questioned in the same case by CBI for three days this week but this is for the first time he was summoned by the ED.
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Tyagi's name cropped at various points in the judgement.
The allegation against him is that he allegedly reduced the height of the VVIP helicopters so that AgustaWestland could be included in the bids.
He took over as the Indian Air Force chief on December 31, 2005 and retired from service in 2007.
ED had earlier submitted that Khaitan was on the board of Chandigarh-based company Aeromatrix which was allegedly a front firm for the financial dealings in the chopper deal.
Tyagi, however, has denied any wrongdoing on his part.
On January 1, 2014, India scrapped the contract with Finmeccanica's British subsidiary AgustaWestland for supplying 12 AW101 VVIP choppers to IAF over alleged breach of contractual obligations and charges of paying kickbacks to the tune of Rs 423 crore by it for securing the deal.
The agency which was supposed to question Tyagi's cousin Sanjiv alias Juli after the ex-IAF chief, has decided to question him at a later date as he was called by CBI today.