A GOLD Coast man has been arrested after the seizure of $78 million of cocaine, the fifth largest haul in Australian history.

Police seized 300kg of the drug from a yacht in Bundaberg on the weekend and more than $3 million in related searches.

The yacht was crewed by two Spanish nationals, a 35-year-old man and a 37-year-old woman. It arrived off Bundaberg on October 20.

Police believe that two other Spanish nationals, a 39-year-old Gold Coast man and a 38-year-old Sydney man travelled from the Gold Coast to Bundaberg on Friday to meet the boat.

All four were arrested on Friday when about 100kg of cocaine was exchanged at the Bundaberg Port.

Investigations are ongoing and police have not ruled out further arrests.

Australian Federal Police national manager for serious and organised crime Kevin Zuccato said it was a highly sophisticated concealment where it was clear the group understood law enforcement and had gone to lengths to escape detection.

"This operation demonstrates that the AFP, with our international and domestic partners, has the capability, resources and commitment to successfully detect and dismantle the most sophisticated organised crime groups," Mr Zuccato said.

"The AFP seized 796kg of cocaine last financial year, an increase of 103 per cent on the previous year."

All four were due to appear in Bundaberg Magistrates Court yesterday and face possible life imprisonment if convicted.