Sydney police have seized 174kg of pseudoephedrine, major material to produce one kind of drugs, hided in coffee boxes in a container from Vietnam.

This volume of pseudoephedrine is estimated at $41 million, enough to process 130kg of drugs, arrived at Sydney Port on August 9.

According to Australian police, this is an international criminal ring and the incident is one of the biggest drug trafficking cases in the history of Australia.

Two men were arrested in Sydney related to this case. Van Thanh Ngo, a Vietnamese Australian, 44 and Peter Thea, 25, were accused of importing this batch of pseudoephedrine.

Sydney police said to arrest some more people in the coming days.

Earlier, a group of Vietnamese were arrested in Melbourne for trading drugs. Police said that this group had brought at least 30kg of heroine into Melbourne and earned more than $20 million in the last nine months.