In a statement, NCB Zonal Director Chennai Zone Amit Ghawate said on specific intelligence received by Indian Coast Guard and NCB, a Sri Lankan fishing vessel 'Ravihansi' was intercepted by the Coast Guard on March 25 in Indian waters off the coast of Vizhinjam, Kerala. 

The NCB Chennai Zonal Unit took over the custody of the boat and seized 300.323 kg of heroin along with five AK -47 Rifles and 1,000 rounds of 9mm ammunition. 

A number of incriminating documents were also seized from the occupants of the vessel, the statement issued here on Wednesday said. 

The heroin was found concealed inside the water tank of the vessel in 301 packets. Image of a flying horse was found on all the heroin packets, which is a usual practice of drug trafficking syndicates to brand their drugs. 

Further, investigations so far indicate that an unknown vessel carried the heroin and arms consignment from Chabahar Port, Iran and handed over the same to Sri Lankan fishing boat Ravihansi in the high seas near Lakshadweep. 

Ravihansi was then trafficking the consignment to Sri Lanka when the Indian authorities intercepted it. 

All the six Sri Lankan crew members namely L.Y. Nandana, HKGB Dassppriya, AHS Gunasekara, S.A. Senarath, T. Ranasingha and D. Nissanka present in the boat were arrested on March 27 by NCB and remanded to judicial custody. 

The intelligence inputs and the investigations so far indicate that a Pakistan-based drug trafficking network was involved in the current seizure. 

There have been seizures of huge quantities of heroin in the Arabian Sea by both Indian as well as other enforcement agencies, which are believed to have been trafficked by the same network. 

This seizure also unveils the nexus between narcotics trafficking and extremist elements.