Firefighters rushed to the scene at a block of flats in the High Road shortly before 1pm last Thursday (June 5).
It took over an hour to bring the fire in a third-floor flat under control.
Metropolitan Police have confirmed that they arrested a woman aged in her 20s at the scene on suspicion of arson with intent to endanger life.
She has since been released under investigation, a police spokesperson confirmed.
The cause of the fire remains under investigation by the London Fire Brigade (LFB) and the Metropolitan Police.
LFB said that one woman left the building before firefighters arrived at the scene, and was assessed by the London Ambulance Service.
Four fire engines and around 25 firefighters responded to the fire, which was under control shortly after 2pm.
