Emergency services rushed to Hector Park, off Rocket Street, just after 3.30pm on Sunday afternoon after reports the 20-year-old male had come off his bike after losing control of it.

Chief Inspector Luke Rankin, Chifley Police District's Crime Manager, said the man, from West Bathurst, was riding an unregistered dirt bike when at around 3.30pm he hit an uneven piece of dirt and lost control of the bike, and was thrown 60 metres.

Police and paramedics attended, and when they arrived the man was unconscious but breathing.

Police were able to rouse him and paramedics worked to stabilise him on the ground.

Chief Inspector Rankin said the man was wearing a full face helmet when the crash occurred but it is thought to have come off as he fell; it was found on the ground not far from the victim.

Paramedics continued to assist the man and the Toll helicopter was called to the scene, landing at Proctor Park, not far from emergency services.

Once stabilised, paramedics placed the victim in the road ambulance and drove him to the waiting chopper, where he was loaded and then flown to Liverpool Hospital to rule out any suspected head or spinal injuries.

The emergency retrieval chopper left the site just after 6pm.

Chief Inspector Rankin said motor bikes are not permitted to be ridden in Hector Park, and police action is pending in relation to riding an unregistered motorbike in a public area.

He said as per usual routine blood samples were also taken from the victim.