The body of a teenage boy was retrieved from the Swartkops River in Port Elizabeth after he went missing while swimming, the National Sea Rescue Institute said on Thursday.

NSRI Port Elizabeth deputy station commander Jonathan Tufts said a duty crew was activated at 17:20 on Wednesday, following a request for assistance from emergency services dispatched to a drowning in progress near the Red House Yacht Club.

"On our arrival on the scene, it was found that during a search for a 13-year-old male who had gone missing in the water while swimming, the body of the teenager was located and recovered from the water," Tufts said.

"Sadly, he was declared deceased."

The Nelson Mandela Bay beach office, police and its diving unit, Coastal Water Rescue and the provincial emergency medical services had been at the scene.

"The body of the child was taken into the care of the Eastern Cape Government Health Forensic Pathology Services and Police have opened an inquest docket," Tufts said.