Two trampers on Mt Cook who activated an emergency beacon on Friday, and spent the night in sub-zero temperatures have not yet arrived at a DOC Hut.
The two men set off their beacon when they suspected one was suffering from hypothermia.
The Search and Rescue Centre says they spent the night in a bivouac shelter at 3500 metres after low cloud cover prevented them being rescued on Friday.
By 10pm on Saturday they had not made contact.
A helicopter carrying two mountain rescue personnel made visual contact with two trampers matching the pair's description on Saturday morning.
The centre says they gave the pilot a thumbs up and appeared to be well.
However, the centre can't confirm they are the ones who activated the beacon.
A spokesperson for the Rescue Coordination Centre, Sophie Hazelhurst says they are waiting for the trampers to make official contact to say they're okay.
She says they are confident the trampers are making there way out of Mt Cook, and can activate their emergency beacon again should they need help.
