The Metropolitan Police are considering manslaughter charges over the Grenfell fire after preliminary results found that the cladding on the tower failed safety tests.
Deputy superintendent Fiona McCormack said the fire was caused by a faulty fridge freezer in a flat within the tower block, but that the fire was not started deliberately.
Ms McCormack said: “Our investigation is seeking to establish how the fire started and the speed that it spread as it took hold of the building.
“We have been told the speed it spread at was unexpected, so importantly we will establish why this happened.
“This investigation will be exhaustive and, as we learn more, the scope and scale may well grow.
“We will examine the construction of the building including the refurbishment.
“Whilst of course we are examining, with experts, the aluminium panelling we are also looking at the entire exterior of the building.
“What that means is the aluminium composite tiles, the insulation behind it, how the tiles were fixed to the building as well as how it was installed.
“Our tests will look at each aspect individually as well as how they how all worked together as part of the building’s cladding.
“Preliminary tests show the insulation samples collected from Grenfell Tower combusted soon after the test started.
“The initial tests on equivalent aluminium composite tiles failed the safety tests.
“Such are the safety concerns with the outcome of these tests we have immediately shared the data with the Department for Communities and Local Government who are already sharing that information with local councils throughout the country.”
Ms McCormack added that the investigation was one of the largest ever undertaken by the Metropolitan Police, with more than 250 specialist investigators involved.
The Superintendent also confirmed that manslaughter charges are being considered, adding: “We are looking at every criminal offence manslaughter onwards. We are reviewing every company involved in the building refurbishment.”
The police have also begun seizing material to be used as evidence into the causes of the fire.
Yesterday the government revealed that samples from 11 tower blocks in eight separate local authorities in the UK had failed safety tests.
In a written statement to MPs, communities secretary Sajid Javid said the tower block owners had been alerted to the safety failure.
Mr Javid said: “So far we have had samples from 11 high-rise buildings in eight local authority areas where the cladding has failed the test.
“All landlords and fire and rescue services for those local authorities have been alerted to the results and we are in touch with all these areas to support and monitor follow-up action.”
Towers across the country are being inspected by landlords, and where a form of Aluminium Composite Material (ACM) is used, samples have been taken for tests.
The government is testing up to 600 tower blocks that it believes have cladding.
Working with the Building Research Establishment (BRE), the government is testing 100 samples a day, and said it had capacity to expand if deemed necessary.
Mr Javid added: “We would urge any landlord who owns a building of this kind to send samples for testing as a matter of urgency.”
Yesterday Camden Council announced plans to strip cladding off five tower blocks in the borough which were found to have cladding which was not specified by the council.
The council is taking legal advice after tests on the cladding of five towers by the BRE found that the outer cladding on the Chalcot Estate towers had been made up of aluminium panels with a polyethylene core.
The Chalcot towers were refurbished as part of a £150m project which saw Rydon act as main contractor on the scheme that was designed by architecture practice HTA. Harley Facades provided the cladding for the project.
According to Rydon, the contract value for the refurbishment totalled £66m. The estate includes four 22-storey towers and another 18-storey tower close to Swiss Cottage.
In a statement, Camden Council leader Georgia Gould said: “The new results from the laboratory show that the outer cladding panels themselves are made up of aluminium panels with a polyethylene core.
“Therefore the panels that were fitted were not to the standard that we had commissioned. In light of this, we will be informing the contractor that we will be taking urgent legal advice.”