Stalin is the third person in his family to be questioned by the CBI.
In 2011, the CBI questioned Stalin's mother Dayalu Ammal and sister Kanimozhi.
Kanimozhi and Dayalu Ammal were questioned in connection with the flow of over Rs.200 crore from Swan Telecom promoter Shahid Balwa's DB Realty firm to Kalaignar TV, a regional Tamil channel in which Karunanidhi's family members allegedly have majority stake.
Later Kanimozhi was charged as co-conspirator in the 2G scam with former telecom minister A.Raja, and lodged in Tihar jail. She is now out on bail.