A 29-year-old man has been arrested over the death of an elderly security guard in Sha Tin on Sunday.

Police said the 69-year-old man collapsed in a car park in the Jat Min Chuen housing estate in the early hours of Sunday and was later declared dead at nearby Prince of Wales Hospital.

Officers believe he and the driver got into an argument and may have scuffled.

"Our preliminary investigation showed that they quarrelled about parking fees. As to whether a fight took place, we are still looking into that," said Kirsten Wong, assistant commander for Sha Tin district.

Wong said the motorist was arrested at the scene. He's also suspected of possessing cannabis.