A stock of heroin, weighing 101 kilos, was taken into custody in the South Sea, while it was on route to Sri Lanka.
The stock was seized during a joint operation carried out by the Sri Lanka Navy and Police Narcotics Bureau.
Fourteen people, including ten Iranians and a Pakistani national, were arrested in connection with the incident.
Police say that the racket was carried out by Sri Lankans with the collaboration of Pakistan and Afganistan nationals.
Sri Lanka Navy said that the illegal drugs are transported to Colombo through the Southern Expressway.