Police would like to talk to anyone who may have witnessed the encounter or seen the man, described as Caucasian in his 40s to 50s of a tall, medium build.
He was last seen heading towards the skate park on Normandy Avenue from Montgomery Crescent after talking to the 10-year-old.
At the time of the incident, the man who has grey toned coloured hair at the base, with longer ginger coloured hair at the top of his head and short brown hair at the back and sides, was wearing dark coloured track pants.
He was also wearing a maroon jacket or hooded sweatshirt.
Please contact Hamilton Police on 07 858 6200 if you are able to assist or alternatively information can be left anonymously with Crime stoppers on 0800 555111.