The Interislander ferry Arahura has been returned to its berth in Wellington after it lost power to its propulsion shafts this morning.
The ferry was left stranded in Wellington Harbour with 61 passengers on board when it was coming into berth in Wellington just before 10am, Interislander said in a statement.
Both of the ship's anchors were dropped and two tug boats were deployed to hold the boat steady.
Interislander said there was no danger to the vessel or its passengers.
Interislander spokesman Michael Flyger said the Arahura had later berthed and passengers and freight were being offloaded.
The ship's master shut down power to the vessel's propulsion shafts after they failed to respond to instruments on the bridge, My Flyger said.
Tests were successfully carried out on its ability to travel forwards, backwards and stop, and the vessel had been assisted into the berth by the Wellington pilot.
An investigation had been launched and Interislander will be working with Maritime New Zealand and the Transport Accident Investigation Commission to determine the most appropriate course of action, Mr Flyger said.
Arahura's scheduled departures from Wellington at 10.30am and 6.30pm have been cancelled and passengers and freight were being transferred onto other services.