A boss at one of the firms behind a flammable insulation used on Grenfell Tower told staff to let concerns about their product "gather dust".
Irish company Kingspan was told by industry certifying body the BBA that there had been "a number of comments" made about the clarity of the wording on the certificate for their Kooltherm K15 product.
The BBA raised concerns about the certificate in December 2008, two months after it was first issued, and suggested several amendments which they offered to make free of charge, according to emails shown when Kingspan employee Andrew Pack gave evidence yesterday.
Mr Pack's then-boss Philip Heath "register(ed) our concern at the proposal to reissue this certificate so soon after publication" and threatened to pass any costs incurred on to the BBA if changes were made, when he replied in March 2009.
Mr Heath - who was at that time a technical manager - then forwarded the email chain on to Mr Pack and several others at Kingspan with the instruction to "let the file gather dust guys".
The inquiry has previously heard about Kingspan using outdated test material to suggest that K15 was safe for use in high-rise buildings above 18 metres tall.
The product sold from 2006 onwards was different from that tested the year before, but the firm kept selling it using the old technology's test pass and only withdrew this information in October 2020.
Giving evidence from Dubai, Mr Pack - now a global technical support manager reporting to Kingspan's Middle Eastern division - agreed when asked by inquiry lawyer Rachel Troup: "Do you agree that is a clear instruction to delay the matter of the proposed amendments?"
Hearings resumed for the first time in nearly two months yesterday after being delayed due to lockdown and other pandemic restrictions.
Evidence is now being given remotely, rather than at the inquiry's base at Paddington in central London.
Grenfell United said in a statement they "well understand how important it is to protect lives and people's health but there is an urgent need to move back to public hearings in a safe way as soon as possible.
"This inquiry is our opportunity to look the people who were responsible for the deaths of our loved ones in the eye."
The inquiry continues.