According to the CBI officials, Gerosa, 70, is one of the three alleged middlemen wanted in this case and his interrogation and statement are very important for both the ED and the CBI who are probing the case.
The ED last year, had notified an Interpol red corner notice (RCN) against Gerosa and two others - Briton Christian Michel James and Italian Guido Haschke - last year.
The CBI has already filed a chargesheet in this case, in which the three are co-accused.
On January 1, 2014, India scrapped the contract with Finmeccanica's British subsidiary AgustaWestland for supplying 12 AW-101 VVIP choppers to the IAF over an alleged breach of contractual obligations and charges of paying kickbacks to the tune of Rs 4.23 billion by it for securing the deal.
The CBI, which registered an FIR in the case on March 12, 2013, has alleged that then Indian Air Force chief S P Tyagi and the other accused received kickbacks from AgustaWestland to help it win the contract. The FIR mentioned charges of criminal conspiracy, cheating and the Prevention of Corruption Act.
The CBI submitted the 30,000-page chargesheet before special Central Bureau of Investigation (CBI) court last year in September.
The CBI named Tyagi's cousin Sanjeev alias Julie, then IAF Vice Chief J S Gujral and advocate Gautam Khaitan as the four Indians in the chargesheet, which mentioned Khaitan as the "brain" behind the deal.
Others named are Italian defence and aerospace major Finmeccanica's former chief Giuseppe Orsi, former AgustaWestland CEO Bruno Spagnolini and middlemen Michel, Haschke and Gerosa.
Orsi and Spagnolini have already been sentenced by an Italian court for bribing Indian officials to get the contract from India illegally.
The CBI said the company was favoured in lieu of illegal gratification accepted through different companies in the name of consultancy services.
According to the CBI, Tyagi took bribes through middlemen and a complex route of companies in several countries, from AgustaWestland to change the specifications of the contract - reducing the operational flight ceiling from 6,000 metres, as originally proposed, to 4,500 metres and bringing down the cabin height to 1.8 metres.
The twin modifications were allegedly meant to rig the deal in favour of AgustaWestland, which eventually walked away with the order to supply 12 choppers for the Communication Squadron of the Indian Air Force for ferrying the President, the Prime Minister and other VVIPs.
Sources said that they mapped the trail of bribes which AgustaWestland paid to bag the deal of Rs 4.52 billion or 12 per cent of the total value of the deal, out of which Rs 4.14 billion came to Indian officials.
The CBI probe revealed that several payments were made to the Tyagis by Haschke, Gerosa and Michel as part of the alleged bribery.
Tyagi, who was Indian Air Force chief from 2004 to 2007, his cousin and Khaitan were arrested in December last year by the agency in connection with the case.