Australian authorities have helped seize 750 kilograms of cocaine destined for the Australian market that was hidden in a luxury yacht in Vanuatu.

The seizure was part of a joint operation with South Pacific countries and the United States drugs agency.

It's one of the largest drug seizures in which Australian authorities have been involved.

The drugs have an estimated street value of $370 million.

Vanuatu police raided the yacht known as the Raj, docked in the Vanuatu capital Port Vila, earlier this week.

There was 750 kilograms of cocaine hidden in the lower engine compartments and around the keel area of the hull.

Officers had to chisel through rocks and concrete to reach the drugs, which were destined for the Australian market.

Australian Federal Police assistant commissioner Ramzi Jabbour said the international drug syndicate's concealment of the drugs was very sophisticated.

He said the seizure had prevented an estimated 750,000 individual drug deals from hitting Australian streets.

There have been no arrests so far but investigations are ongoing.

Mr Jabbour said the same drug syndicate had been involved in another alleged drug importation attempt in 2011, which authorities foiled.

That case is now before the courts.