The probe which was going on for last three years gathered steam with Rakesh Asthana, who was heading the Special Investigation Team probing the case, given additional charge of CBI director after incumbent Anil Sinha hung his boots on December 3.
It was the first-ever arrest of a former chief of IAF by CBI. Tyagi was given bail by the special court with some tough questions for the agency to ponder over.
Another major arrest was that of IAS officer Rajendra Kumar, principal secretary to the Delhi chief minister, in connection with allegations of graft against him.
The high-profile arrest in the national capital triggered a slugfest between BJP and AAP with the latter accusing the Centre of targeting its government because of huge support the party was garnering in Punjab and Goa.
