The Police Dive Squad has been called in the search for a man who went missing at the Whangārei Falls.
Police were called to the falls in Tikipunga at around 4.30pm today.
A man went under the water while swimming and failed to surface.
Whangārei Falls is a popular swimming spot over the summer as well as a popular tourist attraction.
One woman, who did not want to be named, said she was walking her dog at the falls and while she did not see what had happened, she heard a lot of screaming.
Shortly after, Police, Fire and Emergency and St John Ambulance all arrived at the scene.
The woman said someone had told her they were looking for someone in the water.
Groups of people had initially gathered at two viewing platforms at the top of the falls and were looking down at the base of the falls, before police ushered them back and cordoned off the area.
The woman said a group of people were also gathered at the bottom of the falls.
An ambulance at the scene left at around 5.25pm.
The search for the man has now been halted for the evening.
Police said a scene guard would remain at the falls overnight and the search would resume tomorrow with the dive squad.
Whangārei Falls will be closed until the search operation is complete.