Savar , Bangladesh ( CNN ) -- Preliminary results of a government inquiry into last week 's collapse of a nine-story building on the outskirts of Bangladesh 's capital have found that `` heavy machinery and high-capacity generators '' were `` largely responsible , '' according to state media . `` During the inquiry , we have found that use of substandard materials during the construction also contributed to the building collapse , '' committee head Main Uddin Khandaker told Bangladesh Sangbad Sangstha . He predicted the committee would complete its report within a few days . The preliminary conclusion came as police arrested engineer Abdur Razzak Khan on a charge of negligence , Bangladesh Sangbad Sangstha reported . `` He warned that the building was unsafe ahead of its collapse , but he worked as the construction consultant when the Rana Plaza 's owner illegally added three floors '' to the building , the agency said , citing a police official whom it did not identify by name . Two other engineers -- who worked for the municipality of Savar -- have been arrested for having allegedly issued a safety clearance despite the appearance of cracks in the building that appeared the day before it collapsed , the news agency said . The building owner , Sohel Rana , was arrested last weekend as he attempted to flee to India ; owners and senior management of the factories have been arrested for forcing workers to resume production in the building shortly before it collapsed , it said . The death toll from the country 's deadliest industrial disaster rose Saturday to 547 as another 22 bodies were recovered , the agency said . Authorities say more than 2,400 people have been rescued from the wreckage since the building collapsed more than a week ago in this suburb of Dhaka , the capital . The number of dead has risen as workers have begun using heavy machinery to cull through the slabs of concrete , around which hundreds of people awaited news of the missing . The collapse of the building that held five garment factories and thousands of workers has provoked widespread protests in Bangladesh , including attacks on some textile facilities . The demonstrators have expressed anger over the conditions in which many are forced to work . But the trade group that represents the garment industry said Thursday it was safe for the millions of textile workers in and around Dhaka to return to duty . Prime Minister Sheikh Hasina urged residents Friday to delay protests planned for this weekend in the capital so that government workers can focus on recovery efforts . She told reporters she wanted the opposition alliance and Muslim hard-liners marching under the banner of Hefazat-e-Islam `` to consider postponement , not withdrawal of their programs , at this critical point when the people are still fighting for life and rescue operations are under way . '' Bangladesh 's $ 20 billion garment industry accounts for 77 % of the country 's exports . Among those caught up in the finger pointing after the disaster are Western retailers and clothing brands that Bangladeshi suppliers say put heavy pressure on prices , resulting in bad pay and conditions for workers . Bangladesh vs. the U.S. : How much does it cost to make a denim shirt ? The Bangladeshi government has come under criticism from representatives of labor groups who say it has failed to tighten lax safety standards despite a series of recent fatal disasters in the country 's garment industry . In an interview Thursday with CNN 's Christiane Amanpour , Hasina acknowledged that the industry is beset with problems , but said her government is moving rapidly to fix them . Journalist Farid Ahmed reported from Savar , and CNN 's Tom Watkins reported and wrote from Atlanta .
NEW : The death toll rises to 547 as more bodies are discovered . The report is expected to be completed within two working days . Comment: