The gutka scam refers to the illegal sale of chewing tobacco and bribes amounting to Rs 40 crore, paid to influential people in the government and police.

The scam emerged in 2016, during tax raids on gutka manufacturing centres and tobacco barons over tax evasion worth around Rs 250 crore.

Searches at businessman Madhava Rao's home revealed a diary that had names of those believed to have taken bribes from tobacco manufacturers.

Among the code names in the diary were those referring to Health Minister Mr Vijaya Baskar and Chennai police commissioner. Both Mr George and Mr Rajendran have been in that position around the period.

The manufacture, storing and sale of chewing tobacco, including gutka and pan masala, were banned in Tamil Nadu in 2013.

Madhava Rao, whose company makes MDM brand of gutka, was questioned last week at a secret location.

The state's anti-corruption branch, DVAC, initially investigated the scam. In April, on a petition by a leader of the state's opposition DMK, the Madras High Court ordered that the CBI take over.

The CBI registered a case against unidentified officials of the Tamil Nadu government, central excise department and the food safety department in May.

Earlier in January, the court commented on the state government's opposition to a petition seeking that the case be handed over to the CBI. "Why such strong resistance? When there are different agencies and states involved, why cannot the CBI handle the case and the state provide assistance to it?" the court had questioned.