The CBI has questioned former Telecom Minister A. Raja in New Delhi in connection with the 2G spectrum allocation scam. Speaking to reporters, CBI spokesperson Vineta Thakur said Raja was questioned in New Delhi. Earlier, CBI also questioned the Corporate lobbyist Niira Radia and former TRAI Chief Pradip Baijal in this connection. The agency sleuths raided over 30 places in Delhi and Tamil Nadu on December 15 and questioned several people informally. The Supreme Court is closely monitoring the multi agency probe into the allocation of 2G spectrum to certain telecom firms.