Guwahati, Aug. 24: Customs sleuths today stumbled on an ingenious method of smuggling of narcotics when they discovered that the water tank in a coach of the Howrah-bound Kamrup Express contained Manipuri ganja instead of water.

Tipped off, a team of the anti-smuggling unit of the Guwahati customs division carried out an extensive search of passenger coach number 8781 of the Howrah-bound Down 5960 Kamrup Express at Guwahati railway station this morning and found 68 packets of ganja inside the water tank of the bogey.

The consignment, weighing 120kg, is valued at around Rs 6 lakh in the international market.

“One thing is certain. Smuggling the contraband in the water tank is impossible without the connivance of railway staff. We are probing into it,” a customs officer said, adding that this was the first time they came across a water tank of a train being used for concealing narcotics.

He said they would seek help from the railway authorities for further investigation.

There have been no arrests so far.

A case has been registered in this connection under the relevant sections of the Narcotic Drugs and Psychotropic Substances Act.

“The modus operandi behind the smuggling of ganja was ingenious, which took us by surprise,” the source said.

“The initial search of the coach revealed nothing. Since we had definite information from a reliable source about ganja being smuggled in that particular compartment, we decided to take a chance and search the overhead water tanks attached with the coach when the contraband spilled out,” he added.

The ganja was wrapped in newspapers and polythene sheets to prevent its smell from spreading.

The consignment of ganja is suspected to have been loaded at Dimapur and was destined for somewhere in West Bengal.

The officials have seized the entire tank.

“This consignment of cannabis originated in Manipur. Manipuri ganja, which is known for its high quality, has always been high on demand in West Bengal, Bihar, Uttar Pradesh and Rajasthan,” the source said.

“Ganja produced in Manipur is taken to all these places through Guwahati, where the prices are attractive. Guwahati has become a transit hub of contraband smuggling. The Guwahati customs division alone has seized 36,000kg ganja since 2005,” the source said.

He said the inter-state drug cartels are frequently changing their modus operandi and tactics throwing up new challenges for the law enforcing agencies.

There have been past instances of ganja being recovered from secret chambers of trucks.

“In 2005, we had recovered Manipuri ganja from six persons, who were posing as armymen dressed in battle fatigues and were bringing the contraband in two trucks painted in army green,” the source said.