Siliguri, April 24: The preventive wing of the Naxalbari customs seized 2,260kg of cannabis from an LPG tanker at Bidhannagar last night.

Documents seized from the tanker suggest the contraband was headed towards Calcutta. The cannabis is worth Rs 90.4 lakh in the grey market, a customs official said. Nobody has been arrested.

Last week, 51kg of ganja was seized from a parcel at the Siliguri head post office. “But this is one of the largest hauls in a single operation in recent times,” said Harinarayan Meena, the assistant commissioner of Siliguri customs.

Last night’s raid was based on a tip-off. The tanker with the registration number NL07-1516 was parked along NH31 at Bidhannagar, about 40km west of Siliguri. A search of the absent driver’s cabin revealed another number plate, NL05-1827. Both are Nagaland numbers. “We are trying to find out which one is the original and who the owner of the vehicle is,” Meena said.

At first the officials thought the tanker was empty. But a close examination of the valve of the tank, supposed to contain fuel, showed that it had been loosely fixed with bolts. “Had there been LPG, the valve would have been sealed,” said an official.

“Our suspicions were confirmed when we opened the valve and found some packets inside, wrapped in plastic and old newspapers,” he added.

The customs recovered 113 such packets and each of them contained 20kg of cannabis.

“Preliminary investigations suggest that the packets were loaded from Nagaland to be delivered somewhere in or around Calcutta (for probable route, see map),” said Meena.

The cannabis seized is of high quality. “In the grey market, it is known as ‘Manipuri’. The price is also higher, around Rs 4,000 per kg, than local ganja grown in parts of Bihar and in Cooch Behar,” an official said. In Cooch Behar, cannabis sells for as little as Rs 500-1,000 per kg.