Powdered heroin is pictured in this undated handout photo courtesy of the United States Drug Enforcement Administration.
Powdered heroin is pictured in this undated handout photo courtesy of the United States Drug Enforcement Administration. U Reuters/US DEA/Handout via Reu

Some 147 kilograms of heroin bound for Australia from Ranong has been intercepted by Thailand police on Thursday.

The seized drugs were hidden in frozen seafood containers. Its street value was pegged to be at least three billion baht (A$105 million). Police believed the heroin had been smuggled across Thailand's northern border. They claimed it originated in Myanmar.

A Thai and a Malaysian, identified as Kritsana Meenant and Yi Yong Ho respectively, have been arrested and will be charged with possession of illicit drugs for the purpose of resale, the National News of Thailand reported.

Thursday's drug haul, according to Thai deputy police chief Major General Somyot Pumpanmuang, far exceeded what local police had managed to intercept in 2012.

Pol General Pongsapat Pongcharoen, secretary-general of the Office of the Narcotics Control Board (ONCB), said Yi Yong Ho and Kritsana Meenant engaged the services of a marine-life export company in Tambon Bang Rin to repackage the narcotics along with the seafood products to send to Australia.

Two years ago, Thai police seized a total of 127.5 kilograms, according to the UN Office on Drugs and Crime. Mr Somyot said it was a tip from the Australian police that informed them of the illegal drugs.

During the raid, the heroin was found wrapped in 420 packets to be placed in 23 frozen seafood containers.

Heroin is a highly addictive drug derived from morphine, which is obtained from the opium poppy. It is a "downer" or depressant that affects the brain's pleasure systems and interferes with the brain's ability to perceive pain.

It can be mixed with water and injected with a needle. It can also be smoked or snorted up the nose. All of these ways of taking heroin send it to the brain very quickly. This makes it very addictive.