Former Air Force Chief SP Tyagi was arrested today over alleged irregularities in the AgustaWestland VVIP chopper deal worth 3,600 crores, signed when the Congress was in power. He was arrested along with his cousin Sanjeev Tyagi and lawyer Gautam Khaitan after hours of questioning. The former air chief has been accused of abusing his official position by corrupt means. This is the first high-profile arrest made by acting CBI Director Rakesh Asthana, who headed the investigation into the chopper deal before his appointment as the agency's interim chief last week.