Police are concerned for an experienced walker who may have become lost on the Downs.
Michael Wood, who's 67, had been out walking with his wife between Steyning and Pyecombe on Sunday. Near to the Plough Inn at Pyecombe at around 5.30pm, she found he had not kept up with her and she couldn't find him. He was last seen as the South Downs Way crosses the A23.
The couple are visiting Sussex from Canada and Michael does not know the area.
He is white and is wearing a red and black rain coat and a green tweed flat cap. He is fit and an experienced walker.