A sales manager for Suffolk firm Celotex and the makers of flammable insulation used on Grenfell Tower has admitted its marketing was misleading, the inquiry into the fire has heard.

According to inquiry lawyer Richard Millett QC, Celotex’s Rs5000 rigid foam insulation boards were repeatedly advertised as being the first which were “suitable for buildings above 18 metres in height” in promotional brochures.

But the hearing was told on Wednesday that the “extremely important caveat” - that the polyisocyanurate (PIR) insulation had only passed a fire safety test within a specific cladding system, which included fibre cement panels - was not made.

Referring to a Celotex datasheet for customers in which the wording was repeated on every header banner, Mr Millett asked sales manager Jonathan Roome: “Do you accept that those words on the top of those pages in the banner were apt to lead the reader to think that Celotex Rs5000 was suitable for use in all buildings over 18 metres in height?”

Mr Roome, who worked for the firm based in Lady Lane, Hadleigh, between 2014 and 2015, said: “That would be the case, could be the case, yes.”

Mr Millett argued it was “thoroughly misleading”, adding: “It’s misleading because it doesn’t contain the caveat.”

Mr Roome replied: “Yes.”

Mr Millett also referred to a Celotex press release in which product manager Jon Roper said: “Rs5000 will allow contractors, architects and specifiers to use premium performance PIR in externally cladded walls for the first time in high-rise constructions.”

Mr Roome agreed with Mr Millett that it was a “misleadingly general claim because what is missing is the extremely important caveat” that it could only be used with the specific materials which passed the fire test.

The salesman also agreed with Mr Millett that there was “effectively a wall between the sales and technical teams” at Celotex, telling the inquiry: “We were only shown what we were allowed to be shown” in terms of test data.

The inquiry previously heard that Celotex saw Grenfell as a “flagship” for its product and cynically exploited the “smoke of confusion” which surrounded building regulations.

Stephanie Barwise QC, for one group of victims, claimed it actively promoted Rs5000 for use on the 220ft (67m) west London tower block despite knowing it should have been recalled after safety tests.

Neil Crawford, project manager for the architects Studio E, has told the inquiry that Celotex “clearly sought to deceive” architects, saying its “deliberately misleading” sales tactics were comparable to “masquerading horse meat as beef lasagne”.

Celotex, which is part of the French multinational Saint-Gobain group, did describe the cladding system used for the fire test in some parts of its sales literature, but it omitted certain materials and was “not a correct description of the system that was tested”, said inquiry chairman Sir Martin Moore-Bick.

Celotex has maintained it promoted Rs5000’s use on buildings taller than 18m only on a “rainscreen cladding system with the specific components”, used when it passed a fire safety test.

“The rainscreen cladding system described in Celotex’s marketing literature bore no resemblance to the rainscreen cladding system installed at Grenfell Tower,” its lawyer Craig Orr QC has previously told the inquiry.