UPDATE: It turns out an incident in Surfers Paradise this morning wasn't a hit and run.
A man was found lying on Thomas Drive with critical head injuries around 5am.
Police investigations have now revealed he was simply walking along the footpath when he suffered a medical condition and fell, hitting his head.
EARLIER: A man has been taken to the Gold Coast University Hospital with a nasty head injury this morning, after a mysterious incident in Surfers Paradise.
He was found by passers-by at the corner of Stanhill and Thomas Drives around 5am, with one witness telling police the man was wearing a bike helmet, but there was no bike in sight.
It is believed police are treating the incident as a possible hit and run and are on the hunt for the driver.
Anyone who may have seen anything in the area, or who has dash cam footage from around that time, is urged to contact police.