
The ship, owned by Celebrity Cruises, was eight miles north of Cherbourg, France, when the incident happened.
Crew immediately turned the vessel around and headed back towards the spot where their colleague had jumped. They alerted the French coastguard but no trace of the man was found in an overnight search.
Emergency workers called off the search and rescue mission this morning.
A spokeswoman for Celebrity Cruises said: ''Celebrity Cruises' Care Team is providing support to the crew member's family, as well as his friends and colleagues onboard, and our thoughts and prayers are with them.''