Port Otago commercial manager Peter Brown said MS Hanseatic was ''bunkering'' or refuelling at the oil jetty after passengers were dropped off earlier in the day.
The ship carried 184 passengers and 125 crew and stopped in Dunedin during a cruise from Bluff to Auckland.
Mr Brown said it was becoming more common for smaller cruise ships to bunker in Dunedin.
The ship left about 2.30pm yesterday.