The cave-in of the nine-storey factory complex outside the capital last month killed more than 1,100 workers and highlighted appalling safety conditions in Bangladesh's 4,500 garment plants.
"He (Rana Plaza owner Sohel Rana) is the main culprit and because of him 1,127 people have died," said Main Uddin Khandaker, chief of the government inquiry into the April 24 disaster.
"He became rich with black money and started defying all laws and regulations. He is the by-product of our rotten politics and represents the decadent part of our society. He was a terror personified."
"He defied building codes in constructing the building," Khandaker said.
Rana used sub-standard construction materials and did not follow proper specifications, he added.