Police are conducting inquiries into the incident, including examining the possibility the man might have fallen from an upper level of the pub - which was not trading at the time - onto an internal driveway.

However, police will not speculate on whether the man was trying to jump between the hotel and nearby Weltall Casa.

The man has been flown to Westmead Hospital in Sydney for emergency specialist treatment.

Inspector Peter Atkins of Orange police said cleaners at the nearby hotel heard the man calling for help just before 6am yesterday morning.

Police arrived and cordoned off the driveway south of the hotel where the man was found, while ambulance officers stabilised the injured man treating him for head injuries and a fractured leg.

The seriously injured man was placed on a spinal board and his neck was stabilised with a collar before he was transferred to Orange Base Hospital for emergency treatment.

Orange Fire Brigade and a forensic investigation team were also called in after a crime scene was established.

Fire brigade ladders were used to access the roof of the Weltall Casa building on the southern side of the alleyway, to try and find evidence that may assist police in finding out how the man sustained his injuries.

Police have not had an opportunity to interview the injured man.

Inspector Atkins said the hotel closed about 2am, but was not able to say whether or not CCTV footage was available.

The hotel has an external camera system which is trained on certain areas of the exterior of the premises during operating hours.

Police said they are not in a position to say if the man was affected by alcohol.