The police are carrying out an investigation into the death of a diver who was found unconscious in the water with nearly 50kg of cocaine floating around him in the New South Wales Port of Newcastle, Australia.

The diver was found floating in the Hunter River on Monday. The man could not be saved despite the paramedics trying their best.

The recovered cocaine had an estimated street value of £11.3 million. An investigation has been initiated by organised Crime Squad detectives into the incident to find out what transpired before the unidentified man's death.

The police believe that there were two divers who were involved in the task of collecting cocaine from a bulk carrier in the Port of Newcastle and the diver was one of those two men.

Meanwhile, the police have arrested a 62-year-old man in connection with the case. He was arrested by Queensland police and Australian Federal Police at Cairns Airport while he was trying to leave the country for Singapore on Wednesday.

He was charged with importing a large commercial quantity of border-controlled drugs and a large commercial drug supply, according to a report in The Independent.

The police are investigating whether the drugs came from the hull of nearby cargo ship Areti, a Marshall Islands vessel which had arrived in Newcastle from Argentina on Sunday.

Detective Superintendent Rob Critchlow said that the diver was wearing sophisticated dive equipment which included a "rebreather," which lets a person breathe underwater without forming bubbles on the surface.

"This was a well-drilled, professional group ... comfortable sending drugs on a ship across the world. "They knew exactly what they were doing," said Superintendent Critchlow.

Meanwhile, the ship remains docked in Newcastle and is expected to leave for Argentina next week. It is being examined by the Australian Border Force. "We are talking to all the sailors on board and the Captain as well as offshore authorities," said Superintendent Critchlow.

He added that the road between Newcastle and Sydney has become a major target of drug cartels who try and smuggle drugs into the country. They use different tactics which may include secretly attaching drugs to the hull vessels.

cocaine file
File picture: Anne-Marie McLoughlin, 52, Wilmslow, Cheshire, was in possession of 28 grams of 76% pure cocaine worth £1,500. Reuters