Authorities have seized a utility vehicle and are scrutinizing its operator following the tragic death of a young man in an alleged hit-and-run incident in north-west Sydney last night.

A concerned driver contacted emergency services around 7:45 PM after discovering a 23-year-old man unresponsive along Old Kurrajong Road in Richmond.

Despite the swift arrival of paramedics, the man was pronounced dead at the location.

Police established a crime scene, and forensic investigators determined the man had been struck by a vehicle that fled without stopping.

Roughly an hour later, law enforcement responded to reports of a Nissan Navara ute leaving the road, overturning into a paddock along Kurmond Road in North Richmond.

Surveillance footage captured the Navara descending an embankment and coming to rest in thick bushland beside the road.

A 41-year-old man was treated at the scene for minor injuries before being taken to hospital for assessment.

The man is now being investigated by police, but no charges or arrests have been made.

A second crime scene was set up at the paddock where the vehicle will be seized for forensic examination.

Police are investigating if the incidents are linked.

Any witnesses or anyone who has available dashcam/mobile phone footage should contact Windsor police station or Crime Stoppers on 1800 333 000.