Police will allege the syndicate imported more than a tonne of cocaine via NSW ports and included experienced fisherman, marine workers and company owners.

Australian Federal Police Acting Assistant Commissioner Chris Sheehan described the alleged syndicate as "robust, resilient and determined".

He told a packed Sydney press conference that the 15 arrested men were "determined to exploit some of the most vulnerable members of the community."

The seizure of 500kg of cocaine in Sydney, 600kg of the drug in Tahiti and 32kg of heroin in Fiji make it the largest drug bust of its kind in Australia.

NSW Police State Crime Commander Mark Jenkins said all the drugs originated in South America before being transferred across the South Pacific by ship.

Several of the men were arrested on Christmas Day on board a shipping vessel named Dalrymple docked at the Brooklyn Marina on the Central Coast.

It's alleged the boat was used to ferry drugs between NSW ports and a larger ship stationed out at sea that held drugs smuggled from Chile.

Officers from Maritime Border Command and the NSW Police's Marine Area Command had watched the Dalrymple dock at the Sydney Fish Markets for a month before leaving for the Central Coast on December 3.

On Christmas night, officers watched the crew launch a small one-man dinghy which allegedly travelled to Parlsey Bay at Brooklyn on the NSW Central Coast and met with two other men.

All three were arrested and about 500 kilograms of cocaine was seized from the dinghy.

Three other men were arrested on board the Dalrymple vessel as it docked at Brooklyn Marina on Christmas night.

Several other men were arrested in the Sydney suburbs of Zetland, Double Bay, Kingsford, and Greenacre. Two brothers were arrested in Ulladulla, on the NSW South Coast, and two others were arrested in Hobart and Brisbane.

Operation Okesi, comprising officers from NSW Police, Australian Federal Police and Australian Border Force, started over two-and-a-half-years after police received a "thread" of information.

Since then, five alleged importations by the sophisticated syndicate have been thwarted.

It includes the seizure of 32 kilograms of heroin by authorities in Fiji in December 2014 and the seizure of 606 kilograms of cocaine by authorities in Tahiti in March.

A police source told Fairfax Media the syndicate thought they could take advantage of the festive season by striking on Christmas Day.

Authorities valued the total amount of cocaine seized at $360 million.

Among the men arrested is former Eastern Suburbs Roosters player John Roland Boyd Tobin, who played 125 matches as lock forward in the 1980s.

Bondi entrepreneur Darren John Mohr was also arrested. He lists his occupation as the owner Martini Motors and is also the former owner of the Bondi Rescue HQ cafe.

His Instagram profile shows a love of Harley Davidson motorbikes, Rolls Royce cars and being shirtless.

Police also arrested Reuben John Dawe, who lists his occupation as a maritime worker and commercial fisherman Joseph Pirrello, 63.

Other man arrested in the sting include Simon Peter Spero, 56, Graham Toa Toa, 42, Stuart Ayrton, 54, Jonathan Cooper, 29, Richard Lipton, 37, Frank D'Agostino, 54, and Benjamin Sara, 31.

They were all refused bail in Parramatta Bail Court on Monday, Tuesday and Wednesday.

Two other men, extradited from Tasmania and Queensland, will appear in Parramatta Bail Court on Thursday as well as two men arrested in Ulladulla on the NSW South Coast.

Footage released by police show multiple men being arrested in the dark from on-board the Dalrymple fishing vessel.

One of the men shown with his hands tied behind his back is wearing only a pair of boxer shorts covered in cartoon pictures of crocodiles.

"This operation has been running for more than two-and-a-half years and culminated over the Christmas period," a police statement reads.

The men were aged between 29 and 63 years old.  Police are due to address the media at 11am on Thursday.