Alex Dorr, a search and rescue pilot who was part of the team that found missing British backpacker Sam Woodhead, told ITV's Daybreak a helicopter was "scrambled out last night" as they searched in the dark with night-vision cameras in a bid to find him quickly.
He described the area Woodhead went missing in as "very harsh and unforgiving".
Dorr added: "Not that long ago we had a guy who was missing for a much shorter time and he passed away from dehydration."
More top news
Three people who had been arrested on suspicion of murder have been released without any further action.
Zimbabwe's ruling party is to hold a meeting after Robert Mugabe ignored an ultimatum to resign or face impeachment.
The former WTA World No 1 doubles and No 2 singles champion died after a long battle with cancer.