A British tourist, who died along with his American friend when strong winds flipped their kayak in New Zealand, has been named as James Murphy.

The 20-year-old from London was on an expedition with 21-year-old Daniel Hollnsteiner and nine others in Lake Tekapo when the tragedy happened.

The boat reportedly overturned when the weather suddenly changed and the man fell into the water.

The accident took place on Lake Tekapo on New Zealand's south island. Credit: Jocelyn Kinghorn/Flickr

One witness said: "The boats were swamped and they were tipped into the water.

"The air temperature when it happened was about 3C [37F] and the water wasn't much warmer than that and they were in the water for about an hour."

In a statement, New Zealand police said the men were members of a party of 11 friends who ran into difficulty after venturing out on the lake and "being swamped after an easterly wind picked up to an estimated 20 knots."

All of the survivors were treated for hypothermia and three of the party who were admitted to hospital have now been discharged.

An investigation has been launched to look "at the reasons this tragedy occurred", police said.

The Foreign Office said it is providing support to the victim's family.

We can confirm the death of a British national in New Zealand on September 25. We are providing support to the family and are in contact with the New Zealand authorities.

Foreign Office spokesman