A major search and rescue operation is underway after a passenger was reported missing from a Carnival Cruise ship overnight.

The alarm was raised after the man’s family was unable to find him and alerted staff aboard the Carnival Splendor as it made its way down the east coast of Queensland.

“Carnival confirmed on Saturday that Carnival Splendor was assisting authorities search for a guest who apparently climbed over the safety railing and jumped overboard as the ship was sailing from Moreton Island towards Sydney overnight,” a Carnival Cruise Line spokesperson told 7NEWS.

“The male guest was travelling with family who alerted the ship’s crew of a possible missing person and a review of the CCTV footage confirmed the guest’s action.”

Emergency services were contacted and have been assisting in the search for the man, about 53km east of Moreton Island, near Brisbane.

“All appropriate authorities have been alerted and Carnival will assist authorities in their investigation upon the ship’s return to Sydney,” the spokesperson said.

“Carnival’s Care Team is supporting the guest’s family and our thoughts and prayers are with them and their loved one.”

More to come ...