Five drug smugglers, including the kingpin of the racket who is a transport operator and runs two luxury buses between Kolkata and Dhaka, was arrested in the operation that was conducted based on prolonged surveillance and specific intelligence.

The top NCB officers said that this was the biggest haul of heroin in the last five years. The drug was meant to be smuggled into Bangladesh.

NCB zonal director K Shankar said Biswanath Adhikari (49), who owns two Volvo luxury buses that ply between Kolkata and Dhaka apart from a fleet of trucks and intra-state buses, had personally come to collect 36 kg consignment of heroin from a truck on early Thursday morning.

“The truck was coming from Mandsaur in Madhya Pradesh. The drugs were packed in 18 packets of two kg each and hidden in a concealed compartment behind the driver’s seat made for this purpose. Ravi Shankar Pandey of Ghazipur (UP), Gopal Teli and Shyamlal of Rajasthan were travelling in the truck. During interrogation, it was revealed that Pandey was a Bengal contact and had rented a residence in Panagarh in Burdwan district. A search of his house resulted in the seizure of a another 10 kg of heroin,” Shankar said.

The fifth person to be arrested has been identified as Buro, a trusted aide of Adhikari, who had come to pick up the contraband with him. Adhikari owns a two-storied bungalow in Bongaon and a flat in the upmarket Rabindra Sarobar area.

“Raids are going on at Adhikari’s Bongaon residence. We are investigating to ascertain if he used his transport vehicles to smuggle drugs. At the moment, we suspect the drugs were being smuggled across the border using people on foot. While this particular consignment came from MP, he may have been procuring from UP and Rajasthan as well. All three states officially grow poppy for pharmaceutical purposes,” Shankar said.

The NCB officers said Adhikari was known to be the biggest smuggler in the Bongaon area and had been operating the racket for nearly seven years. They added that he received consignments once or twice every month, a small part of which found its way into the city.