A case has been filed against Nicol Tamang, the prime accused in the murder of All India Gorkha League president Madan Tamang, after he escaped from CID custody in Pintail village near here even as efforts were on to trace him. "Nicol is yet to be found. All police stations in Darjeeling district have been alerted so that Nicol cannot escape to Nepal," Darjeeling Superintendent of Police, Mr Devendra Pratap Singh, told PTI. He said CID officer Aniruddha Chatterjee and constable Arabindo Kumbhokar, who were in charge of his custody at a house used by the CID in Pintail village have been suspended. A case has been filed against Nicol, a close aide of Gorkha Janmukti Morcha president Bimal Gurung and a central committee member of the party, at the Pradhanagar police station, he said. Bharati Tamang, president of the All India Gorkha League alleged that the escape of Nicol was a conspiracy by the West Bengal government.