A man has been arrested in north Queensland while allegedly trying to flee the country as police investigate the death of a mystery diver found near bricks of cocaine at a NSW port.

Police identified the scuba diver as a foreign national after he was found unconscious in the water and later died on Monday at the Port of Newcastle.

Police also found 54 kilograms of cocaine in the vicinity and believe the diver had been trying to retrieve the packages.

A 62-year-old man was arrested over the drug haul as he attempted to fly to Singapore about 5.30pm on Wednesday.

He has been charged with importing a large commercial quantity of border controlled drugs and a large commercial drug supply.

NSW detectives from the Organised Crime Squad are travelling to Cairns to seek his extradition when the man appears in Cairns Magistrates Court on Thursday.

Police say the dead diver had sophisticated dive gear, including a “rebreather” apparatus that allows divers to breathe underwater without any telltale bubbles rising to the surface.

Authorities have searched the Marshall Islands-registered Areti cargo ship, investigating theories the drugs may have been thrown from the ship or attached to its hull, and the diver may have drowned while trying to retrieve them.

The ship arrived from Argentina on Sunday and remains docked in Newcastle.

It is unlikely the diver, if linked to the drugs, was acting alone, NSW Police Detective Superintendent Rob Critchlow said on Tuesday.

“These people have fled so it’s quite disgusting that this man’s been left to die regardless of what he was involved with,” he said.

AAP