Ferry services departing from the Downtown Auckland ferry terminal have been cancelled or diverted while police continue to scour the area for a man who was last seen in the water early this morning.

The police dive squad will scour the water this afternoon and searches continue around the ferry terminal in downtown Auckland for the man. The Deodar police boat and the Eagle helicopter have also been deployed.

The search is affecting ferry services running from the Downtown Ferry Terminal for the rest of the day.

About 400 ferry passengers travelling to and from Half Moon Bay will have to use a replacement bus service leaving from Queen's Wharf after the service was suspended from 2.30pm. Five ferry services were scheduled for tonight with the last one leaving at 7.30pm.

Advertisement

Waiheke services have also been relocated and will now leave from Pier 1C to Waiheke Island after 4pm.

An Auckland Transport spokesman said the changes were due to the police operation at the Downtown Ferry Terminal. Passengers are being warned to expect delays on other ferry services as they complied with Police requests.

The changes were in place until further notice or police advised otherwise.

"We apologise for the inconvenience but appreciate your patience and understanding," an AT tweet said.

Police believe they know the man's identity and, as they try to establish what happened, are keen to speak to two men he was speaking to before he ended up in the water.

Police were called to the area about 4.35am this morning and have been searching for the man since.