A 54-year-old Hong Kong man died after reportedly losing control of an electric bike and falling from an unloading platform in Yuen Long early on Sunday, with the incident only discovered more than five hours later.

Police received a report at 9.21am that a man was lying unconscious on Tong Yan San Tsuen Road. Officers arrived at the scene and found the man, surnamed Lam, with head and hand injuries. He was pronounced dead at the scene.

According to the force, Lam was riding the e-bike eastbound when the accident happened at around 4am.

Police said the rider was believed to have lost control near a goods unloading platform, causing the bike to plunge off the 1.25-metre (4.1-foot) drop.

The case is being handled by the New Territories North traffic investigation team. Anyone who witnessed the incident or has information is urged to contact officers at 3661 3800.

Electric mobility devices fall under the definition of a motor vehicle under the Road Traffic Ordinance, meaning unregistered or unlicensed use may constitute an offence.