Indonesia has seized a record 1.6 tonnes of crystal methamphetamine from a ship, which had been to Australia, off the northern island of Batam, the second major drug bust this month.
Budi Waseso, head of the anti-narcotics agency, said authorities had acted on a tip from Chinese and Thai authorities and that the shipment had come from Myanmar in a vessel disguised as a fishing boat.
"It had been to Australia... and in and out of Indonesian waters several times. This means this ship had repeatedly entered Indonesia carrying large quantities of narcotics," Mr Waseso said.
President Joko Widodo's government has cracked down on trafficking in an effort to contain soaring consumption of crystal meth and other narcotics.
There has been no bloody war on drugs as in the neighbouring Philippines, where thousands of people have been killed in anti-drugs operations.
Indonesia has among the world's strictest anti-narcotics laws and drug trafficking is punishable by death.
The United Nations Office on Drugs and Crime (UNODC) estimates that Southeast Asia's trade in methamphetamines and heroin was worth US$31 billion (NZ$42 billion) in 2013.
Earlier this month, Indonesian authorities confiscated just over 1 tonne of crystal meth, known locally as 'shabu-shabu', also in Batam, a small industrial hub a short ferry ride from Singapore.
Myanmar is part of the so-called Golden Triangle where it meets Thailand and Laos and where drug production and trafficking is booming.