Agents of India’s Central Bureau of Investigation (CBI) have formally launched an investigation into an alleged kickback scheme that the CBI says helped British helicopter manufacturer AgustaWestland Ltd. land a $750 million deal in 2010 to sell a dozen AW 101 helicopters to transport the country’s top officials.

After several properties were searched in New Delhi and two nearby cities on Wednesday, the CBI named 12 suspects, including retired Indian Air Force chief Shashi Tyagi and three of his cousins, as well as AgustaWestland and its parent company, Rome-based Finmeccanica SpA (BIT:FNC), according to OneIndia News.

The move opens the way for India to make arrests and to ask for information from Britain and Italy. Former AgustaWestland CEO Bruno Spagnolini and Finmeccanica Chairman Giuseppe Orsi are already under house arrest in Italy, which has launched its own inquiry into the alleged kickback deal, according to Reuters.

India says that through an American intermediary named Guido Ralph Haschke and another man identified as Carlo Gerosa, the company execs facilitated payments to Tyagi and others to ensure that AgustaWestland would win the contract. The CBI says that Tyagi and two of his cousins, identified as Dosca and Julie, received at least some of their bribe money through engineers working in Tunisia and Mauritius.

The British firm has already delivered three of the helicopters and over $200 million has already been paid. No arrests have been made so far, but India has temporarily blocked further payments. Facing parliament on Wednesday, India Defense Minister A.K. Antony declined to offer further details.

The scandal first emerged last year, and Antony had previously criticized Italy for denying past requests for investigations into the alleged bribery deal.

AgustaWestland Ltd., based in Farnborough, U.K., makes light single-turbine helicopters, tiltrotors and Apache combat helicopters for the British Army under a license agreement with American aerospace giant The Boeing Company (NYSE:BA). Finmeccanica SpA is a technology-based industrial company operating with six divisions, including aerospace, which produces military and civil aircraft.