The Tazreen Fashion's fire safety license expired in June this year and the owners had not subsequently applied for a new one, the fire department's administrative director Abdus Salam told AFP.

"Its license for 2011-12 year expired on June 30 this year and they did not come to us for renewing the fire safety certificate for 2012-13. We approve licenses after inspecting factory conditions," he said.

The 110 staff at the Tazreen factory were killed when a fire ripped through the nine-storey building on November 24 on the outskirts of Dhaka.

The victims, who were mostly women paid as little as $37 a month, found themselves overcome by smoke or jumped from elevated windows. Firefighters have told AFP that all three of the fire exits led to the ground floor.

The factory was supplying clothes to a variety of international groups including US giant Walmart, Dutch retailer C&A, Hong Kong supplier Li & Fung as well as to the brand owned by US rapper Sean "Diddy" Combs.

Salam said none of the factory's fire equipment was used during the blaze and that initial investigations found that the inferno did not originate from an electric short circuit as was feared initially.

Salam said the official government inquiry team would submit its report in the third week of the month. Its initial investigations pointed to "arson or sabotage" as the main cause of the incident.

Authorities have previously said that the nine-storey factory only had permission for three floors.

There have also been accusations that managers instructed employees to stay at their work stations when the fire broke out and told them that the activation of a fire alarm was only a routine drill.