Manslaughter is among the charges being considered in relation to the Grenfell Tower fire , a Metropolitan Police detective has confrmed.
Detective Superintendent Fiona McCormack who is overseeing the investigation into the fire which killed at least 79 people, said documents and materials had been seized from a "number of organisations".
"We are looking at every criminal offence from manslaughter onwards, we are looking at every health and safety and fire safety offences and we are reviewing every company at the moment involved in the building and refurbishment of Grenfell Tower."
The chief executive of Kensington and Chelsea council has resigned after coming under a barrage of criticism for the council's handling of the 24-storey tower bock.
Speaking to reporters outside New Scotland Yard, Ms McCormack confirmed that a faulty Hotpoint refrigerator caused the fire , but said that police know the fire was not started deliberately.
Ms McCormack said police are working with experts to examine the aluminium cladding, the insulation behind the cladding, how the tiles were fixed to the building and how it was installed.
"Preliminary tests on the insulation samples collected from Grenfell Tower showed that they combusted soon after the test started. The initial tests on the cladding tiles also failed the safety tests," she added.
"Such are our safety concerns on the outcome of those tests, we have shared our data with the Department of Communities and Local Government (DCLG) and we have ensured that information data has been shared with every council.
The recovery operation is well underway at Grenfell Tower, but police expect they will continue to work on the site until the end of the year.
Describing how the investigation was proceeding, she added: "We have been in Grenfell Tower, from top to bottom, last week.
"Next week we will be installing a lift to the outside of the building to assist. But our forensic search may not be complete until the end of the year."
Keep up to date with the latest news in west London via the free getwestlondon app.
You can set up your app to see all the latest news and events from your area, plus receive push notifications for breaking news.
Available to download from the App Store or Google Play for Android .
