Updated

Sri Lankan customs agents have seized 250 kilograms (550 pounds) of heroin worth $19 million from a container sent from Pakistan, in what an official says was the largest-ever stock of heroin nabbed in South Asia.

Customs director Mali Piyasena says the heroin was found Friday at a terminal in the capital, Colombo. The heroin was concealed inside 17,500 small grease cans packed into a large container sent from the Pakistani city of Karachi.

Piyasena says a Pakistani national and three Sri Lankans were arrested in connection to the seizure and will be handed over to the police narcotics division after the completion of a customs investigation.

He says it was the largest-ever haul of heroin seized in South Asia.