Directorate of Revenue Intelligence investigators had intercepted five persons and seized heroin worth 100 million rupees at the Central Railway Station in Chennai.
The five, arrested on Saturday, included the mastermind, a man of Sri Lankan origin, as well as two women.
Officials said that the seizure of trafficked heroin was among the largest haul in the State in recent times.
DRI officials said that they received information that four persons from Madhya Pradesh were smuggling close to 6 kg of heroin by train from Bhopal to be handed over to a Sri Lankan man in Chennai.
We spoke to police media spokesperson SP Ajith Rohana regarding drug smuggling operations between India and Sri Lanka and the special measures put in place to curb the trade.