"It is thought that the boy had been submerged for nearly three minutes and was unresponsive when plucked from the water," Wicks told Sapa.

"They [paramedics] arrived to find that the boy had been pulled from the water by his swimming coach, South African Olympic swimmer Terence Parkin."

The boy was taken to the Garden City hospital and was in a stable condition.

Wicks said he could not confirm The Star report that the boy had been sucked in by the vent.

Parkin won a silver medal at the 2000 Olympics