( CNN ) -- The Australian navy has destroyed nearly 353 kilograms ( 780 pounds ) of heroin after intercepting the drugs on a smuggling vessel off the coast of Tanzania , the Australian Department of Defense said Friday . Authorities estimate the street value at 706 million Australian dollars ( $ 630 million U.S. ) . A team from the aircraft carrier HMAS Melbourne boarded the smuggler ship Wednesday during a sweep , according to a prepared statement . It tested the substance on board , determined it to be heroin , then confiscated it . Members then extracted samples and destroyed the rest .
The Australian navy has destroyed nearly 353 kilograms ( 780 pounds ) of heroin . In the first half of this year, Australia seized more than 100 tonnes of cocaine and almost 500 kg of methamphetamine from boats in international waters off its east coast. A team from the aircraft carrier HMAS Melbourne boarded the smuggler ship Wednesday .