Police divers are searching for the body of a 23-year-old man after he went swimming in the Bloupan Dam in Kempton Park on Saturday afternoon, paramedics said.

"It is believed a family were enjoying their day at the dam when a group of men decided to go for a swim in the dam. It is believed one of the men got into difficulty while swimming and disappeared under the water," said Netcare911 spokesperson Chris Botha.

Botha said paramedics were standing by while Saps divers search for the man's body.