Four fire engines and around 25 firefighters were called to reports of smoke issuing from the basement of an office block and hostel on York Road in Battersea.
Firefighters arrived to find smoke logging in the ground floor offices, but didn't find any evidence of a fire. It is believed a smoke cloak was activated causing smoke to fill the building.
The Brigade was called at 2031 and the incident was over for firefighters by 2219. Fire crews from Chelsea, Wandsworth, Clapham and Battersea fire stations attended the scene.