Passengers aboard a cruise ship that ran aground in Papua New Guinea (PNG) on Saturday will be flown back to Australia, after efforts to refloat the vessel failed.

The Australian-flagged Coral Adventurer became stuck on a reef off the eastern coast of PNG at around 05:25 local time on Saturday.

The 80 passengers and 44 crew members are safe and unharmed, and the passengers, who departed from Cairns in northern Australia on 18 December, will be flown back there.

The same ship made headlines earlier this year when it left behind an elderly woman on a remote island on the Great Barrier Reef. Her body was found the following day, and an investigation is ongoing.

In the latest incident, the Coral Adventurer was transiting through Morobe, Madang and Sepik provinces when it hit strong sea currents and sailed onto the reef, Morobe’s Police Commander Chief Superintendent Samson Siguyaru told the ABC’s Pacific Beat programme.

The ship was on a six-degree list to the port side – meaning it was tilting to the left, the NMSA said. After inspections, authorities determined that the vessel was not damaged, and there was no environmental pollution or spillage.

However a detention notice has been issued, Ch Supt Siguyaru said, which means the ship has been deemed unseaworthy – at least temporarily – and is not allowed to leave the location “until all the processes are cleared”.

Attempts on Sunday to free the ship by using its own engines and a tug boat were unsuccessful, PNG authorities told the ABC.

The ship’s operator, Coral Expeditions, said on Monday that it would end the tour a day early and fly passengers back to Australia, the public broadcaster reported.

According to its website, Coral Expeditions has been running tours to PNG for about 20 years.

Morobe’s provincial governor, Rainbo Paita, told the ABC that the vessel took a route not usually used by local operators because the reef is known to be “very high there”.

Coral Expeditions has been contacted for comment.