A drone has been used to search for a missing teen who was swept away during a night swim in a river last night.
Police are currently searching the mouth of Hutt River, Wellington Harbour and riverbanks for the 19-year-old.
A dive squad has not yet been deployed as the river's condition is too dangerous at the moment, Sergeant Anthony Harmer said.
"A drone was deployed earlier to search areas where people are unable to reach."
Two young men went swimming last night around 10.30pm near Belmont School. When one got out of the water he could no longer find his friend.
The area where they were swimming is not typically a popular spot as it is very deep, wide and the currents can be unpredictable, Harmer said.
Search teams were scouring the area last night.
Greater Wellington Regional Council river ranger Travis Moody said the river was at its peak when the youth entered the water.
"It gets quite ferocious, even in a smaller rain event like that. Any time the river's up you don't want to get in the water.
"It's a raging torrent basically. You'll have big boulders underneath the water moving along with that flow."
Moody said the man would have struggled to keep his head above water in those conditions.
"Even if you did get to the side, you'd have to deal with a whole lot of vegetation.
"It's pretty easy to get pulled under when it's like that, poor guy."
Police established that the two young men spoke to a man and woman in the Belmont Domain area at some stage last night and ask the couple to call Police on 04 381 2000.
If anyone else spoke to two young men in the Belmont Domain area, Police also ask for them to come forward.
The search effort is being aided by Wellington Land Search & Rescue, the Hutt Community Emergency Response Team, Upper Hutt Community Rescue, Wellington Coast Guard, Wellington Harbour Rangers, and New Zealand Fire Service.
Police ask members of the public to avoid the river area at the moment so that staff can concentrate on the search. The river is still very high with a fast-moving current so is not safe for swimming.