CBI on Tuesday questioned the secretary general of Delhi Commonwealth Games organising committee Lalit Bhanot for alleged financial irregularities in the Games. Earlier the investigating agency questioned a close aide of CWG organising committee (OC) chairman Suresh Kalmadi. On Monday, the CBI grilled three personal staff members of Kalmadi in connection with the recovery of a broken CD and a letter demanding 4 crore rupees from him. All three OC officials were questioned for about five hours at the CBI headquarters. The broken CD would be sent to the Central Forensic Science Laboratory for a forensic examination to retrieve information from it.On Friday, CBI officials, who raided Kalmadi’s premises claimed to have recovered a letter at his Delhi bungalow, in which there was a demand for 4 crore rupees in exchange for a CD that allegedly contained damning information about the OC chairman. The CBI sources said the sender of the letter threatened to make the disc public. AIR correspondent quoting sources said, key files containing information on tendering, budgetary allocation and contract details were missing from the OC office.