The type of cladding used on the exterior walls of a London tower block that went up in flames this week was not graded fire-resistant and its use is restricted in the US.
The aluminium cladding, called Reynobond, was made by US company Arconic and had a polyethylene core, which the reports said was slightly cheaper than fire-resistant models by the same manufacturer.
It was fitted by a company called Harley Facades, which has put out a statement following Wednesday's blaze saying: "We are not aware of any link between the fire and the exterior cladding of the tower."
The Times newspaper quoted a Reynobond salesman as saying that in the United States the panels were banned for buildings taller than 40 feet, far lower than the 24-storey Grenfell Tower that was consumed by the roaring blaze.
The residential tower was built in 1974 and had been extensively refurbished in works that were completed last year.
The Daily Telegraph listed several other fire safety concerns about the building, including the lack of a central sprinkler system and missing fire doors. The paper also said that the last full assessment of fire risks for the building was in December 2015, before the refurbishment was completed last year.