'Most perfect sister': Woman swept away in Waikato River named

The brother of a woman who drowned after being swept down the Waikato River has written a heartfelt tribute to his "best friend and most perfect sister".

Aucklander Rachael Louise De Jong, 21, was one of four friends caught out when a floodgate at the Aratiatia Dam, north of Taupo, opened at noon on Monday, sweeping them down the river.

Three of the group, all also in their early 20s, managed to make it to the riverbank, but Ms De Jong's body was later found downstream.

The Aratiatia Rapids north of Taupo. Photo: Supplied

Posting a touching tribute to Facebook, her brother Daniel De Jong said he has "lost one of the most important people" in his life.

"Not only was she an inspiration to us all, she was my best friend, and the most perfect sister I could've ever asked for."

Meanwhile, police and Mercury Energy say a warning siren went off before the floodgate opened and there were signs warning against swimming posted in the area.

RELATED: One dead after woman swept down Waikato River

The death has been referred to the coroner.

The incident happened during one of the several times the gates open each day on a regular schedule.

Photo: Google Maps

It was one of four other water deaths across the country over Waitangi weekend.

Police on Tuesday also named a man who died after coming up from a dive near Tolaga Bay, north of Gisborne, as 54-year-old Wiremu Tuakana Teneti-Northover of Outer Kaiti.

– With NZN