The CBI has summoned Tamil Nadu Health Minister C Vijaya Baskar and former state minister B V Ramanaa for questioning in connection with the alleged gutka scam on Saturday, officials said.
Three other people have also been asked to appear before the agency, they said.
The questioning will be conducted in Chennai, and a CBI team will reach the city Friday night, the officials said.
The Tamil Nadu government had banned gutka (a concoction of tobacco and pan masala) in 2013, and it is being alleged that bribes were paid to bureaucrats, ministers and politicians to allow its manufacturing and sale.
The scam came to light on July 8, 2017 when income tax sleuths raided the godown, offices and residences of a Tamil Nadu-based pan masala and gutka manufacturer who had been facing charges of tax evasion to the tune of Rs 250 crore.
The promoter-directors of Jayam Industries -- A V Madhav Rao, Uma Shankar Gupta and Srinivas Rao -- allegedly sold MDM brand gutka by influencing officials, politicians and regulatory authorities, the agency officials said.
Jayam Industries was rechristened to Annamalai Industries to continue the sale, they said.