jon roper told the hearing that celotex was desperate to take business from a rival firm.up the cheating, which he admitted amounted to fraud. our home affairs correspondent tom symonds has the details. in 2014, celotex was desperate for its insulation panels to be picked for the refurbishment of grenfell tower, but three years later, the insulation installed behind cladding panels was blamed for helping the flames to spread. this is the standard lab test to prove how building systems handle fire. here, they're testing cladding panels. testing is crucial for manufacturers trying to break new products into markets. the inquiry heard that in 2014, celotex effectively rigged the test carried out on its insulation. did that not strike you at the time as dishonest? yes, it did, yeah. but you went along with it? i went along with a lot of actions at celotex, that looking back on reflection were completely unethical. after one failed test, celotex commissioned this rig, which contained less insulation and extra magnesium oxide boards, which don't burn. celotex used the test resul