A raging inferno gutted about 25 homes at the Riverside Beach Club on the Vaal in Vanderbijlpark on Sunday.
An investigator from the Intelligence Bureau SA said firefighters and emergency officials who responded to the scene said they believed that a gas canister had exploded.
The damage caused was estimated to be around R100m.
Pictures of the devastating blaze were posted on the Intelligence Bureau Facebook page.
The fire reduced the thatched-roof homes, vehicles, including a Porsche, and jet skis to tin and ashes as a large plume of smoke filled the air.
Intelligence Bureau SA said some of the house owners had rolled out their hoses and tried to douse the large flames.
It was alleged that a firetruck which arrived on scene, did little to help the situation as it was without any water.
According to the Intelligence Burea SA, only one person sustained injuries in the blaze.
It was unclear how badly the woman had been injured.
She had been taken to hospital.