The main contractor behind the refurbishment of Grenfell Tower have been accused of being ‘disingenuous’ in claiming that other companies made the key decisions on the project.
Several sub-contractors who worked on parts of the refit have refused to comment on their work until they have full disclosure of documents, the probe was told on Monday.
Stephanie Barwise QC, representing survivors and the bereaved, said their silence was "inhumane" and claimed that Rydon, the main contractor, was being "disingenuous" about its involvement.
She told a hearing at Holborn Bars in central London: "CEP, the sub-contractor which purchased and fabricated the Reynobond panels, claims it cannot participate at all until it has had full disclosure.
"If CEP wishes not to incriminate itself, that is its choice - but it is disingenuous of CEP to plead inability to comment on the compliance of its own work.
"The same applies to Harley (facades), as it does Studio E (architects).
"These parties make no comment on the detailed criticism of their work, nor do they even comment on drawings that they themselves drafted.
"Significantly, they do not indicate how they proposed to achieve compliance (to building regulations), assuming, that is, that they ever applied their minds to that question."
Expert reports released on Monday identified the cladding system installed on the building as the main reason the flames shot up the side of the tower block.
Ms Barwise then hit out at the effect the refusal of corporate bodies to engage would have on the inquiry process.
She said: "These contractors should not be allowed, by their deliberate refusal to participate, to derail determination of the compliance issue even though we are concerned with blatant non-compliance.
"Despite their words of condolence to the victims, these corporates have no desire to assist this inquiry, even though their participation could save lives in the immediate future.
"The inability to produce a basic account how, if at all, they considered Grenfell Tower complied with the building regulations is itself indicative of the culture of non-compliance which expert Dr Barbara Lane has identified.
"The corporate silence deprives the families of the degree of resolution and understanding to which they are entitled and has only served to increase their pain and uncertainty.
"It is inhumane to remain silent when so many seek understanding and answers - answers which are within the corporate's gift."