A fan factory in Gazipur, which was ravaged by a devastating fire, had been operating without proper permission.
The authorities made the disclosure after inspecting the site on Monday, a day after 10 people were killed in the blaze.
The factory owners also failed to obtain a fire licence while the premises lacked adequate fire safety measures, according to the Fire Service and Civil Defence.
The bodies of the 10 victims were identified and handed over to their loved ones on Monday, reports bdnews24.com.
Two others were injured in the fire that broke out on the second floor of Rouza High-tech's three-storey 'Luxury Fan' factory in the Sadar Upazila's Kashorita.
The factory authorities did not obtain any permit from the Department of Inspection of Factories and Establishment, said the department's Joint Director General Farid Ahmed.
They rented a local building and carried out operations at great risk under a tin shed on the second floor.
"No rules were followed in setting up the factory. They didn't even apply to the factory authority for permission," said Farid.