The anti-corruption branch of the Central Bureau of Investigation has called Dravida Munnetra Kazhagam chief M Karunanidhi’s secretary Shanmuganathan for questioning concerning the 2G scam, The Times of India reported. The CBI has also called former Tamil Nadu intelligence chief Jaffer Sait and former Kalaignar TV head Sharad Kumar for a preliminary inquiry. The television channel is owned in part by the DMK chief’s wife Dayalu Ammal, and daughter, Kanimozhi.

The CBI’s move comes two days after DMK leader MK Stalin sent a legal notice to Marumalarchi Dravida Munnetra Kazhagam chief Vaiko, for alleging that he was involved in the 2G scam. DMK leader and former Telecom Minister A Raja was arrested in 2011 for his involvement in the scam, along with Kanimozhi. Both were later let out on bail. Raja’s former associate Sadiq Batcha had committed suicide in 2011, when the investigation was on.

The scam was a major poll plank in the 2011 Tamil Nadu elections, and is expected to come up in the upcoming state elections as well. Elections in the state are scheduled for May 16. Other issues being brought up at pre-poll rallies are the recent floods in the state, and Chief Minister J Jayalalithaa’s disproportionate assets case.