The incident happened at around 3pm on April 26, on a path near the Wildbrook estate in Port Talbot. Now police are asking for anyone with information to help them trace the man.
A police spokesman said a 65-year-old man was approached by the suspect, who demanded money from him.
The suspect is described as being male, white, aged mid 20s, 6ft 1in-2in in height, of slim build and dirty appearance.
He was wearing a woollen beany-style hat, faded jeans which were covered in mud, a padded jacket and a black T-shirt. His appearance is described as being generally scruffy. One of his trainers was tied with string.
The suspect made off in the general direction of Tanygroes Place.
Anyone who recognises the suspect from the description is asked to call police on 101 or Crimestoppers anonymously on 0800 555 111 FREE quoting occurrence number 1600148771.