When the cruise ship Celebrity Solstice left Port Chalmers about 7pm yesterday, it did so minus a male passenger.
Senior Sergeant Kelvin Lloyd said police had been notified about the missing man, who had left items, including his passport, on board.
''We are hopeful he will make contact with us, or the boat ...
''The longer he doesn't make contact, the more the concern will grow.''
The vessel, which can carry 2850 passengers and 1500 crew, was due in Akaroa this morning.