Sources said the taskforce interrogated the two secretaries SM Zafrullah and Shahid Alam in the conference room of the works ministry for over two hours in the afternoon.

SM Zafrullah, former public works secretary, and Shahid Alam, former civil aviation and tourism secretary, were made OSDs following the filing of the graft case against them.

Assistant Director of the Anti-Corruption Commission Shahidul Alam filed the graft case against SM Zafrullah and Shahid Alam with Motijheel Police Station on March 29 for selling the 18 abandoned houses in the capital's posh areas of Gulshan, Banani, Dhanmondi and New Eskaton through fake auction.

The other accused in the case are former minister for housing and public works Mirza Abbas and nine serving senior bureaucrats.

Their alleged abuse of power caused the government a financial loss of over Tk 127 crore.