Police are urging members of the public to come forward with information after a man was killed in a suspected hit-and-run incident in the Sydney suburb of Freshwater on Saturday. Image: News Corp

Police are investigating the cause of a mysterious hit-and-run on Sydney’s northern beaches, which claimed the life of a 66-year-old man.

Antonio “Tony” Plati was found early Saturday morning on Oliver St in Freshwater, conscious with serious head injuries.

He later died at Royal North Shore Hospital.

Detective Chief Inspector Michael Boutouridis said police were canvassing the possibility the man was struck by a car and left for dead.

“At this stage very early in the investigation we think it was possibly a hit-and-run,” he said.

“But given it was dark and it was raining at the time and the man (Tony Plati) was wearing dark clothing, there’s a good chance the driver was unaware they were involved in a collision.”

A neighbour, Jill Farrell, said she rushed outside with blankets and umbrellas when she spotted the injured man on the road, according to Nine News.

The 66-year-old man was struck about 400 metres from his home, The Daily Telegraph reported.

It reported Mr Plati walked the route each morning to the beach, and returned by 9am to be a full-time carer for his 103-year-old mother.

“If anyone was on Oliver St near Brighton St at Freshwater at quarter to six (Saturday) morning, I’d like them to come forward. They might have some dashcam, might have seen something before or soon after which could help us in our investigation,” Inspector Boutouridis said.

Police investigations are ongoing.

Anyone with information about this incident is urged to contact NSW Crime Stoppers on 1800 333 000.

— with AAP