In a massive drug bust, nearly 2,500 kilograms of methamphetamine worth around Rs 12,000 crore was seized from a vessel in Indian waters along the Kerala coast in a joint operation by the Navy and the Narcotics Control Bureau NCB, the anti-drug agency said on Saturday. The NCB said it was the largest seizure of methamphetamine in the country and a Pakistani national has been detained in connection with it.