CBI is likely to start questioning suspects this week in connection with its ongoing probe into alleged kickbacks in the Rs 3,600-crore VVIP helicopter deal.
CBI sources said the agency is likely to call former air chief SP Tyagi and his cousins for questioning.
They said they are planning to question all the accused who are present in India, but did not elaborate on which suspects will be summoned initially.
The agency has already issued look-out notices against Tyagi and other accused to prevent them from leaving the country, they said.
CBI has named 10 Indians in the FIR, including former IAF chief SP Tyagi, besides brother of former union minister Santosh Bagrodia, Satish Bagrodia, and Pratap Aggarwal, chairman and managing director of IDS Infotech respectively.
The former air chief and his cousins Sandeep, Julie and Docsa Tyagi have been accused of alleged association with European middlemen Carlo Gerosa and Guido Haschkhe who worked for Italian firm Finmeccanica to clinch the deal in favour of its UK-based subsidiary AgustaWestland.
CBI has alleged that middleman Haschke, through his Tunisia-based company Gordian Services Sarl, entered into several consultancy contracts with AgustaWestland from 2004-05 onwards and "almost on back-to-back basis he also made consultancy contracts with the Tyagi brothers (Tyagi's cousins)," the sources said.
Under the cover of these contracts, Haschke allegedly sent €1.26 lakh and €2 lakh to the Tyagi brothers.
"Besides these two remittances, Tyagi brothers also received some unquantified sum of money from the middlemen (Haschke and Gerosa)," the FIR said.
"The inflow of remittances to Tyagi brothers and softening of IAF's stand on service ceiling of the helicopter closely match in terms of time," the FIR said.
According to the FIR, "Haschke and Gerosa managed to send €5.6 million through Mohali-based IDS Infotech and Chandigarh-based Aeromatric Info Solutions private limited to India and kept the remaining amount out of about €24. 3 million received from AgustaWestland with themselves in the account of IDS Tunisia".
"A portion of this amount was sent to India through Mauritius and hawala route in order to pay kickbacks in India for swinging the VVIP helicopter deal in favour of AgustaWestland," it said.
CBI also alleged that AgustaWestland managed to introduce a comparative flight trial with non-functional engine and eventually succeeded in getting the contract for supply of 12 AW-101 VVIP helicopters from the defence ministry mainly due to softening of the IAF on service ceiling after Tyagi took over as its chief.
The agency alleged that out of total €51 million kickbacks paid by AgustaWestland, British middleman Christian Michel was paid about €30 million.