He was walking home along Ancastle Green when he heard voices behind him.
When he turned round he saw one man on the pavement and two others hiding behind a tree and a car.
He told police later that all three then approached him and asked for his mobile phone. He said he did not have it so the offenders took his watch instead. Two of them then went through his pockets and stole his wallet before running off towards Gravel Hill.
The incident happened in the early hours of July 7.