The CBI has sent notice to former Telecom Minister A Raja to appear before it for questioning in connection with the 2G spectrum scam. The move comes after the CBI raided 34 places in Delhi and Tamil Nadu on the 15th of December and questioned several persons informally. AIR Correspondent, quoting official sources, reports that similar notices have been sent to others, including corporate lobbyist Niira Radia while her close associate and former Chairman of the Telecom Regulatory Authority of India, Pradip Baijal was being questioned by CBI sleuths on Monday.