Police in India have arrested former air force chief SP Tyagi over allegations of corruption in a luxury helicopter deal with Anglo-Italian company AgustaWestland.
The Central Bureau of Investigation (CBI) said Mr Tyagi had given the company “undue favours” and had channelled funds to bribe others.
Indian authorities filed a criminal case against the firm and its parent company Finmeccanica in March 2013.
Mr Tyagi previously denied the charges.
His cousins Julie Tyagi and Docsa Tyagi have also been arrested on charges of taking bribes, the CBI said.
The scandal came to light after Finmeccanica’s chief Giuseppe Orsi was arrested in Milan in 2013.
The Italian authorities said they had been investigating him for bribery and embezzlement for several months. Mr Orsi has denied any wrongdoing.
Italian investigators also named Mr Tyagi in a preliminary inquiry submitted to an Italian court.
India’s defence ministry cancelled the $753m (£597m) 12-helicopter deal in 2014, after announcing that it would carry out its own investigation into the matter.
The luxury helicopters were intended to carry the Indian president, prime minister and other VIPs.