Two people are missing after a collision between a jet boat and a jet ski near Queenstown.
Search and Rescue says there's little hope of finding them alive.
The incident happened at about 7.30pm on Monday on the Kawarau River near Frankton.
A search will resume at first light on Tuesday. It's understood they were residents of Queenstown.
Another man and a woman were flown to Dunedin Hospital with serious injuries.
Dunedin Hospital says the man has been transferred to a general ward and his condition has stabilized. However, the woman is still in a serious condition in intensive care.
All involved are understood to have been on the river together.