LONDON — India’s Central Bureau of Investigation (CBI) has registered cases against specific individuals as it investigates corruption in the tainted VIP helicopter deal with AgustaWestland.

The CBI says it is investigating 13 people it suspects are involved in bribery surrounding the purchase of 12 AgustaWestland AW101 VIP helicopters purchased for the Indian air force in 2010. India has suspended all payments and threatened to cancel the purchase altogether if the charges of bribery to middlemen both in India and abroad are proven.

As part of its investigations, the CBI announced it has registered cases against the former chief of the Indian Air Staff at the time of the purchase and the CEOs of six companies — two in India, one in Italy and one in the U.K., as well as companies based in Mauritius and Tunisia.

CBI officials have conducted searches at 14 locations in Delhi, Gurgaon, Chandigarh and Mohali. CBI’s case is based on the allegation that several individuals acted as middlemen and influenced the deal in favor of AgustaWestland, the agency says.

“[An] Italy-based company paid commission in terms of several millions of euros to the middlemen,” the agency adds. “The middlemen from their share of commission allegedly paid huge sums of money to some Indian nationals in the garb of engineering contracts with two India-based companies.”

The Indian investigation was prompted by the arrest in Italy of the chairman and CEO of Finmeccanica Giuseppe Orsi, and the CEO of AgustaWestland, Bruno Spagnolini, who was placed under house arrest by Italian authorities who have also been investigating the deal. Orsi has since stepped down from the company and has been replaced by Alessandro Pansa. Spagnolini has been replaced by Daniele Romiti, who was installed as CEO of AgustaWestland on Feb. 28. Orsi was head of AgustaWestland when the deal with India.

The scandal is also threatening to overshadow another Indian weapons deal for the purchase of Black Shark torpedoes with another Finmeccanica division: Whitehead Sistemi Subacquei (WASS).

The announcement from the CBI comes just days after Romiti pledged “full transparency” with investigators. He said he was confident that the aircraft’s selection was made in a “competitive environment.”

The CBI’s investigation continues.