The new Australian Federal Police Drug Strike Teams, together with the Australian Customs Service and the NSW Police Service, have made Australia`s largest ever heroin seizure involving an estimated 400kgs of heroin, conservatively valued between $300 and 400 million.

Following a sophisticated intelligence driven operation, 18 men are in custody on a range of drug-related offences.

It is alleged that the men arranged to pick up the heroin from a mothership which sailed into NSW waters near Port Macquarie and a small runabout was used to take the drugs from the mothership to a secluded beach.

A joint agency team involving AFP, Customs, the NSW Police and the Joint Asian Crime Group which includes members of the National Crime Authority, arrested the men after the drugs had arrived at the beach.

Those arrested are expected to appear in court later today.

This seizure dwarfs the previous record heroin seizure of 123.4kgs made in Darwin in 1994. The seizure represents nearly three times the amount of heroin seized in Australia last year (138 kgs).

More importantly, this operation has disrupted the operations of an organised criminal syndicate with clear international connections.

AFP Commissioner Mick Palmer said that the Strike Team operation was a clear reflection of the potential benefits of the Federal Government`s recent Tough on Drugs initiatives.

"This success demonstrates our enhanced capacity, and the knowledge, to systematically put these groups out of business. The message is clear - their chances of getting caught are going up all the time.

"The AFP is indebted to our international law enforcement partners, in particular, the Hong Kong Police and to the Australian Customs Service and the NSW Police Service for the specialist resources they provided during this operation.

"Arresting drug runners in remote areas, late at night, and with boats involved, requires expert personnel and equipment and unavoidably a significant level of danger.

"The courage and professionalism shown by everyone involved should not be underestimated.

"The successful resolution of this operation reflects great credit on the skills of all personnel both on the ground and behind the scenes.

"Drugs are bad news for Australian society, however, the Strike Teams and the cooperation we are now seeing across agencies has the potential to make a real difference and this is an example of it," Mr Palmer said.

The Chief Executive Officer of the Australian Customs Service Lionel Woodward, said the success of this operation demonstrated the benefit of the Customs Coastwatch combined air surveillance and marine response capabilities.

"The sophisticated equipment on the Coastwatch aircraft played a vital role in the outcome," he said.