The stock of heroin seized in Southern seas has been estimated to be worth over Rs. 2.32 billion.
The Sri Lanka Navy in a statement said five persons were apprehended with 290.2kg of heroin while transporting the stocks in a multi-day trawler.
The group was escorted to the shores earlier today. The stock of narcotics had been concealed in 259 packs.
The Navy said the group had set out to sea on the 30th of July and officials suspect the stock of narcotics was obtained from foreign drug traffickers who use international shipping lines.
The group of suspects, aged between 31 and 37 years, are residents of Ahungalla, Balapitiya and Habaraduwa.
The Police Narcotic Bureau and the Sri Lanka Navy are conducting further investigation.