A carelessly-discarded cigarette could have caused a fire that ripped through a nine-storey block on Saturday night and forced 38 people to evacuate.

The blaze at Florin Court, in Charterhouse Square, Finsbury – a building made famous as the home of TV detective Poirot – took hold at 9.45pm and ravaged a first floor flat and damaged one on the second floor before it was extinguished almost an hour later.

Four engines, including one from under-threat Clerkenwell, tackled the blaze.

The exterior of the Art Deco building was also damaged by smoke

A spokesperson for the London Fire Brigade (LFB) said: “We believe the fire was accidental – most likely caused by a cigarette.

“None of the occupants were smokers, so it’s possible someone threw a cigarette out of a window or off a roof terrace, which then blew into an open window in the bedroom. Wherever you’re smoking, it’s crucial to make sure you put out cigarettes fully before disposing of them, particularly in dry conditions.

“Never, ever throw a lit cigarette out of a window – you have no control over where it ends up, and it could cause a great deal of damage and upset to you or someone else. It’s very lucky no one was injured in this fire.”