POLICE trying to unravel the mystery surrounding a man's death are keen to speak to four men seen travelling in a Ford Fiesta.

Andrew Hickox died in York District Hospital days after he was found unconscious in the city's Lower Friargate at 1.15am on Saturday, July 20.

Detective Sergeant John Roberts, leading the investigation into the 42-year-old's death, said witnesses had reported seeing a man fitting Mr Hickox's description having an argument with the men in the Fiesta shortly before he died.

"The maroon Fiesta was travelling down King Street. A pedestrian spoke to the occupants and some sort of altercation or argument may have taken place," said Det Sgt Roberts.

"That pedestrian may have been Andrew Hickox. The vehicle turned left from King Street to Lower Friargate, the man walked up Clifford Street and turned right."

Following further scientific tests, police are now certain that Mr Hickox, a father-of-three from Elland, near Halifax, died after being struck by a vehicle, but that he was already lying in the road when hit.

Officers also want to speak to a man who approached two women in the area and asked them for a cigarette. He told them that a man had been injured in Lower Friargate.

He is described as white, about 6ft, with light brown hair and was wearing a dark long-sleeved shirt over his trousers. Det Sgt Roberts said he may be a crucial witness.

He said: "Someone knows what happened to Andrew Hickox. I will ask them to search their conscience and to contact the police with any information which will assist this investigation. The number to call is (01904) 618503."