The cavity barriers used on the refurbishment of Grenfell Tower were only formally approved as safe by the supplier nine days after the disastrous 2017 fire, the inquiry has heard.

Cavity barrier supplier Siderise had sold the barriers for use on Grenfell Tower for gaps ranging between 326mm and 425mm - despite the product only being tested to a maximum cavity of 300mm.

But Monday’s hearing was told how, in the immediate aftermath of the fire which claimed 72 lives, the firm had ordered a report which extended the application of the barriers to gaps of up to 425mm.

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