A search is underway for a person reported to be in trouble on Lake Wakatipu, in Otago.

Jet boats, a helicopter and other swimmers are helping with the search effort, police said.

A police spokesperson said officers and ambulance were notified that a person was in trouble in the water at the head of the lake, near the reserve, about 4pm today.

“Efforts are under way to locate them, jet boats and other swimmers are currently assisting,” the spokesperson said.

 “A helicopter has also been assisting.”

A Glenorchy resident said another resident told her there was a water rescue about 4pm today.

She heard helicopters overhead and could see one flying low over the Glenorchy Wharf.

Members of small settlement had discussed the need for a sign to warn the public since last week’s death, although no action had been taken yet, the resident said.

Another resident said there were boats searching on the lake, as well as helicopters.

The area near the wharf had a steep drop-off, at a nearly 45-degree angle going down to a 21m drop.

Eddies at the mouth of the Rees River made the area north of the wharf ‘’treacherous’', as they could pull unsuspecting swimmers out.

Several drownings had happened as a result of this around Lake Wakatipu over the last two decades, the resident said.

It follows a search last week for two people who were swept away at the same spot near Queenstown.

Leroy Kaaho (48), also known as Linkin Kisling, of Wanaka, died trying to save his two sons, aged 10 and 12, when they apparently became caught in the river’s current on January 13.

Emergency services were first called to Lake Wakatipu at Glenorchy at about 2.55pm on Friday, Kisling had entered the water to assist a person but failed to exit the water himself.

A St John spokeswoman said an ambulance, a first response unit and a helicopter were sent to the scene on Friday.

One patient with minor injuries was taken to Lakes District Hospital by road.

A second helicopter was stood down before it arrived at the scene, the spokeswoman said.