Hong Kong police have arrested eight people in connection with the suspected murder of a 51-year-old man in Tuen Mun, the Post has learned.

A source said on Tuesday that those apprehended were believed to have been involved in a dispute over the sale of illicit cigarettes.

Another insider said that the victim, identified as Hong Kong identity card holder Zeng Pengshan, was found on Monday under a bridge over Yick Yuen Road with a knife wound to his head.

The source added that the wound on the back of his head was believed to be fatal.

A passer-by, who was on their way to work, discovered the victim unconscious and covered in blood at the scene. No suspicious persons were seen at the location at the time.

A private car with bloodstains inside and on the rear was also found near the scene, with officers suspecting it was connected to the case.