A cyclist swallowed by a sink hole in Waihi faces possible paralysis after breaking his back.

The man was out riding his bike near Morgan Park, off Kenny Street, when he got stuck in a metre-deep sinkhole.

The man fell into a sink hole in Morgan Park. Photo: Google Maps

A local council worker found the man trapped in the sinkhole while out collecting rubbish early yesterday.

An Auckland-based Westpac Rescue Helicopter spokesperson says the man was suffering from hypothermia as he had been out all night.

Waihi Fire Brigade chief fire officer Moe Stevens says they were called to Morgan Park about 4.45am to help lift the man.

Moe says the man was unable to get out of the hole due to his injuries.

'I'm not sure how long the man had been there,” Moe says. 'It was in a grassy area, on a slight rise near a tree, and it must have been dark when he was riding.”

The injured rider was treated by St John Paramedics from Waihi and Paeroa before being driven to Paeroa, where he was flown to Auckland City Hospital with serious injuries.

The sinkhole near Morgan Park.