The passenger fell off the Spectrum of the Seas in the Singapore Strait en route to the city-state, Singapore’s Maritime and Port Authority said.

The authority said its maritime rescue coordination centre was leading a search and rescue operation to find the missing passenger.

The crew of the Cyprus-flagged ship was “supporting with investigations”, the centre said.

The ship’s operator, Royal Caribbean International, said crew members had immediately launched an effort to find the missing passenger.

“The ship has since been cleared by the authorities and sailed as scheduled on Monday evening,” it said in a statement.

An itinerary showed the vessel was due to depart Singapore today on a 12-night cruise to Japan.

The operator did not give further details, citing “privacy and respect” for the missing person’s family.