"Initial investigations indicate that the fire is suspicious and police are appealing for anyone with information which could assist them with their investigations to come forward," she said.
A Dreamworld spokeswoman said the theme park was operating as usual despite the nearby fire.
"There is visible smoke coming from that area but not enough to stop rides," she said.
"There was an announcement over the system to let visitors know the smoke was nearby and there's no cause for concern.
"The Big Brother house is not in Dreamworld but it's on land owned by the Queensland Investment Corporation."
QFES warned smoke might affect motorists on the motorway, north of Exit 54.
"Motorists in the area should drive with caution and to conditions," the alert said.
"Nearby residents affected by smoke should close their windows and doors, and keep any necessary respiratory medication close by.
"If residents are concerned their property is under threat they are advised to call triple zero immediately."