The Narcotics Control Bureau (NCB) seized two kg of heroin worth Rs six crore, that was recovered by the Border Security Force during a raid in West Bengal's Murshidabad district, a senior NCB official said on Monday."The BSF troopers recovered two packets of heroin from a group of Indian smugglers near the Indo-Bangladesh border on Sunday morning."The packets were later handed to the NCB," the bureau's Kolkata unit head Dilip Kumar Srivastava said in a release."Looking at the pattern, it seems the contraband was prepared in Murshidabad's Lalgola," he said.According to the official, the group of smugglers were challenged by the BSF personnel but none could be arrested as they fled taking advantage of darkness and thick vegetation in the border area.The seized heroin would be produced in the Berhampore court under the Narcotic Drugs and Psychotropic Substances (NDPS) Act later on Monday.