An air search is underway for an 84-year-old passenger who has gone overboard from a cruise ship east of Sydney.

Australian Maritime Safety Authority spokesman Mal Larsen says the man went overboard at 9 p.m. local time (10:00 GMT) on Monday off the Sun Princess 280 kilometers (175 miles) east of Sydney.

Larsen says the cruise ship, which is operated by Princess Cruises, has remained in the area rather than continue to Sydney where it was due on Tuesday.

He says an airplane is conducting the search on Tuesday.

Larsen does not know the circumstances in which the man went overboard or how quickly the alarm was raised.