Two trampers from Invercargill have been winched to safety near Westport after becoming exhausted on the Old Ghost Road track.

The two men, aged 71 and 78, activated a personal locator beacon around 8.30am this morning.

A rescue helicopter searched the area and winched the men to safety just after 11am. They were flown to Buller hospital in Westport, though there were no injuries.

One of the men was suffering from extreme exhaustion and activated his locator beacon after spending the night stuck on a spur.

The men had started a five-day walk on Tuesday, and were due out on Sunday.

Conrad Reynecke, of the Rescue Coordination Centre New Zealand, said the trampers were well-prepared and equipped, but the terrain got the better of them.

"They found themselves unable to continue the tramp and have done the right thing in activating their beacon before their condition got worse."