Kochi: In a massive drug bust, nearly 2,500 kilogram 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.

Giving details of the seizure at a press conference held here, NCB officials said it was carried out as part of 'Operation Samudragupt' which targeted maritime trafficking of drugs originating from Afghanistan.

This is the third major seizure by NCB of maritime trafficking of drugs through the southern route in the last one and a half years, the agency said.

As part of the operation, so far around 3,200 kg of methamphetamine, 500 kg of heroin and 529 kg of hashish has been seized, it said.

The agency claimed that the latest consignment was meant for India, Sri Lanka and Maldives from Afghanistan.

The drug cache had started on a "mother ship" -- a large vessel that distributes narcotics to various boats during its journey -- from the Makran coast around Pakistan and Iran, it said.

As many as 134 sacks of suspected methamphetamine, the Pakistani national, the intercepted boat and some other items salvaged from the ship were brought to Mattancherry Wharf and handed over by the Navy to the Narcotics Control Bureau, it said. "NCB has initiated the seizure procedures and the primary analysis is that all of the packets contain methamphetamine of high purity," the NCB said.