The plastic core of the cladding used on Grenfell Tower could have burned as quickly as petrol, a fire safety expert has said.
The energy output from the burning building would have been equal to burning 51 tonnes of pinewood, research by the University of Leeds as reported by the BBC has suggested.
Dr Roth Phylaktou, an expert in fire investigation at the university, said the cladding combined with insulation was "optimum for vertical fire spread".
He told the BBC: "If you set that on fire near the bottom you can imagine what would happen and how fast the fire will grow."
Before the blaze Grenfell Tower had been recently refurbished with Reynobond PE cladding, consisting of Reynolux-coated aluminium sheets over a Reynobond polyethylene core.
Dr Phylaktou said: "The polyethylene in the cladding would have burnt as quickly as petrol."
The BBC said it had seen information released by French authorities which indicates the burning cladding would have released 14 times more heat than a European standard of "limited combustibility".
All buildings over 18 metres which have submitted cladding samples have failed combustibility tests rolled out after the fire, the Department for Communities and Local Government said on Tuesday.