The Central Bureau of Investigation (CBI) is all set to file a supplementary chargesheet in the 2G spectrum scam today. The chargesheet comes nearly three weeks after the first one which named former Telecom Minister A Raja, top telecom honchos and bureaucrats. Sources in the CBI say that M Karunanidhi's daughter, Kanimozhi, and his wife, Dayaluammal, will both be accused of benefiting from the scam.