After the pair – a 26-year-old woman and a 30-year-old man who were travelling with family and friends – were unaccounted for during the debarkation process at the Sydney Overseas Passenger Terminal, the authorities were contacted and searches began.

The New South Wales (NSW) police said an air and marine search and rescue operation was under way off the coast of Forster – more than 130 miles north of Sydney.

Officers from the Marine Area Command reviewed CCTV footage and determined the pair had gone overboard about 8.50pm local time on Wednesday.

A spokesman for NSW police said: “Police and Australian Search and Rescue have determined a search area approximately 60Nm east of Forster and have deployed aircraft and marine vessels.

“Officers are investigating the circumstances surrounding the disappearance of the pair and, in these early stages, are focused on the search efforts.”

A spokesman for Carnival Cruise Lines said: “We have naturally been concerned since we became aware that two passengers were missing from Carnival Spirit and our thoughts are clearly with their families at this difficult time.

“We are working closely with New South Wales Police and assisting them in their inquiries.

“At approximately 9.15am today during the debarkation process for Carnival Spirit at the conclusion of a 10-night cruise in Sydney, it became apparent that two guests, a 26-year-old woman and a 30-year-old man, were unaccounted for.

“The ship immediately initiated standard missing person procedures including a full search of the vessel as per protocol. The guests in question were travelling with family and friends and initial reports indicate that the couple were last seen onboard the vessel last night.”

Cruise fall couple may have been arguing, claims police source

A couple who went overboard from a cruise ship off the coast of Australia on May 8 had been arguing before the fall, a senior police source told the Associated Australian Press.

The incident occurred on the Carnival Spirit as it sailed along the mid-north coast of New South Wales.

CCTV captured Paul Rossington and Kristen Schroder in the ship’s casino on Wednesday evening having a heated argument, which led them to skip dinner with Ms. Schroder’s family.

Later footage shows the pair ‘mucking around’ in the ship’s corridor, apparently no longer arguing. The couple then head to the deck of the ship where Ms. Schroder can be seen climbing over the Spirit’s railing, facing the sea.

Around 8.50pm, the footage shows the couple going overboard into the Tasman Sea, one immediately after the other. Police have been unable to determine whether Ms. Schroder jumped or fell, but Mr. Rossington can be seen jumping overboard moments later.

The search for the pair was called off last Friday afternoon after police had searched 500 square nautical miles off the coast of Forster, NSW.

Carnival Australia has defended the company’s safety standards, saying rails on the ship are higher than required by international regulations.