"There was some crack at the second floor, but my factory was on the fifth floor," Muhammad Anisur Rahman said. "The owner of the building told our floor manager that it is not a problem and so you can open the factory."

He initially said that his firm had been sub-contracted to supply Wal-Mart Stores Inc, the world's largest retailer, and Europe's C&A. In a subsequent interview he said he had been referring to an order in the past, not current work.

People rescue a garment worker who was trapped under the rubble of the collapsed Rana Plaza building in Savar, 30 km (19 miles) outside Dhaka April 24, 2013. [Photo/Agencies]

Wal-Mart did not immediately respond to requests for comment. C&A said that, based on its best information, it had no contractual relationship with any of the production units in the building that collapsed.

The website of a company called New Wave, which had two factories in the building, listed 27 main buyers, including firms from Britain, Denmark, France, Germany, Spain, Ireland, Canada and the United States.

"It is dreadful that leading brands and governments continue to allow garment workers to die or suffer terrible disabling injuries in unsafe factories making clothes for Western nations' shoppers," Laia Blanch of the UK anti-poverty charity War on Want said in a statement.

November's factory fire raised questions about how much control Western brands have over their supply chains for clothes sourced from Bangladesh. Wages as low as $38.50 a month have helped propel the country to no 2 in the ranks of apparel exporters.

It emerged later that a Wal-Mart supplier had subcontracted work to the Tazreen factory without authorisation.

Buildings in the crowded city of Dhaka are sometimes erected without permission and many do not comply with construction regulations.