He said visits to all the hospitals in Savar and Dhaka where the injured and the dead were taken had proved fruitless.
"Nobody can tell me about my nephew, who was working at an apparel factory in the building," he said.
Much of the rage voiced in protests has been directed at Sohel Rana, the owner of the building, who was arrested near the Indian border over the weekend. Protesters have called for him to be hanged.
Rana and the owners of the factories in his building have been accused of ordering workers to enter the premises on the day of the collapse, despite the discovery of large cracks the day before.
The Bangladeshi government is also coming under criticism for lax enforcement of safety regulations in factories and claims by Britain and the United Nations that it refused offers of help with rescue efforts.
Home Minister Mahiuddin Khan Alamgir said Tuesday that the rejection was because Bangladesh had only wanted equipment to be sent, not the additional search and rescue experts offered by the outside agencies.
EU considers trade action
In a sign of the growing international pressure on Dhaka to improve labor conditions, the European Union said Tuesday that it was considering trade action against Bangladesh. The statement carries weight, since the EU is Bangladesh's largest trade partner.
The Bangladeshi government said this week that it would begin inspecting the safety and security of all garment factories in the country.
Major Western retailers and clothing brands, some of which sourced products from the factories in the collapsed building, are also facing difficult questions about how closely they scrutinize working conditions at their suppliers.
"We understand that businesses operating in this building appear to have links to numerous companies in the U.S. and Europe and so we'll continue to engage with U.S. companies to discuss what role they can play in improving working conditions, including in Bangladesh," U.S. State Department spokesman Patrick Ventrell said Wednesday.
The catastrophic building collapse happened about five months after a fire at Tazreen Fashions Factory, a garment maker in another suburb of Dhaka, killed at least 112 people.