Malda, April 7 : The Special Task Force of West Bengal Police has seized heroin worth Rs 12 crore and arrested a couple for possessing the contraband drug from the border district of Malda, about 350 kms north of Kolkata in north Bengal, police said on Thursday. The drug, weighing about 2.5 kgs was concealed in a music system, belonged to an international gang engaged inclandestine business in the border districts of West Bengal and Bangladesh and elsewhere, the police investigatingthe drug cartel trade in the district said. The arrested couple, identified as Riya Shalin ( 20 and Golam Mostafa (25), are the residents of Lalgola, Murshidabad, also a border district of West Bengal with Bangladesh. The seizure and arrest happened on Wednesday night as the sleuths of the STF following an input laid a trap in the English Bazar,close to the Railway station, overpowered them when the duo was attempting to flee whilst being frisked. PC KK