Hundreds of passengers were stuck on Viking Orion off the coast of Australia after a potentially harmful growth was found on the ship’s hull.

It was denied permission to dock in Adelaide after authorities found an accumulation of microorganisms, plants and algae or small animals, which could have imported invasive species into the natural habitat.

Officials insisted the ship must be cleaned by a specialist team of divers before entering Australia.

The ship, which carries 930 passengers, was reportedly forced to skip four ports of call after also being denied permission to dock at Christchurch and Dunedin in New Zealand and Hobart in Tasmania.

Passengers weren’t allowed to leave the ship after it left Wellington in New Zealand in the early hours of Boxing Day till 2 January when it arrived in Melbourne.

However, according to the cruise ship tracking website Vesselfinder, Viking Orion spent just four hours in Melbourne before leaving at just after midday yesterday to sail to Sydney, where it is due to arrive early tomorrow morning.

In a statement, Viking said: “   The Viking Orion arrived in Melbourne, Australia on 2 January (local time) and was admitted to port. The ship has now returned to her planned itinerary and is currently sailing toward Sydney, where she is expected to arrive on 4 January (local time).

“Following the exterior cleaning of a limited amount of standard marine growth (commonly known as marine biofouling or algae) from the ship’s hull—a routine cleaning procedure for nautical vessels—the ship unfortunately missed several ports on this itinerary.

“Viking is working directly with guests on compensation for the impact to their voyage.”

One guest tweeted that they had been offered 50% future cruise credit, but a Viking spokesperson told Travel Gossip guests had been offered a voucher valued at 100% of what they’d paid Viking, which can be used for any future cruise.

Media reports said Princess Cruises’ Coral Princess was also subjected to cleaning on 23 December due to an infestation of snails, which forced it to skip part of its itinerary.