CBI is expected to call DMK MP and Tamil Nadu chief minister M. Karunanidhi's daughter Kanimozhi for questioning in connection with the 2G spectrum scam.
Agency sources said the questioning may take place before the CBI files the chargesheet in the case on March 31.
Kanimozhi holds 20 per cent stakes in Kalaignar TV, where a company linked to one of the accused in the scam Shahid Balwa, had invested.
She was in the news over conversations with corporate lobbyist Niira Radia as revealed by the leaked telephone calls tapped by the income tax department.
Meanwhile, CBI director A.P. Singh met public accounts committee chairman Murli Manohar Joshi on Thursday in connection with the 2G spectrum allocation scam.
Singh had appeared before the PAC last month and told the members it was wrong to say that there was "zero loss" to the national exchequer as a result of the 2G spectrum allocations.
The probe agency had assured the Supreme court that it will file the first chargesheet about its investigation into the scam that took place during the regime of A. Raja by March 31, 2011.