Man questioned over Bronte hit-and-run

A 36-year-old man is in police custody over an alleged hit-and-run in Sydney's east, which has left another man in hospital fighting for his life.

Police say a man was arrested on Wednesday morning on unrelated matters and is at Chatswood Police Station being questioned about the Bronte incident.

A passing motorist found a 26-year-old man lying in the middle of the road on St Thomas Street in Bronte about 2am on Wednesday.

Paramedics treated him at the scene and he was rushed to St Vincent's Hospital with critical head injuries where he is now undergoing surgery.

At first, police were unsure whether the man had a skateboarding accident after a skateboard was found nearby, or he was the victim of a hit and run.