Metropolitan Magistrate Mohammad Ahsan Habib gave the order after Hasnat Karim was presented in the court on Monday on completion of his eight-day police remand, Dhaka Tribune reported.
The court fixed August 24 for hearing a bail petition filed by Hasnat, a former North South University teacher.
Humayun Kabir, an inspector of the Counter Terrorism and Transnational Crime unit and the Investigating Officer, told the court that Hasnat had given important information about the terror attack, which investigators were verifying, and that he should be kept in jail until the investigation is completed.
Masudur Rahman, Deputy Commissioner of Dhaka Metropolitan Police, told reporters at his office that police would not seek fresh remand for Hasnat for some time.
"The information we got from Hasnat during his two-term remand is being scrutinised," he said.
The law enforcers will seek remand for him in future, if necessary, Masudur added.
Hasnat was arrested on August 3 in the case linked with the killing of 22 hostages, including 18 foreigners and two policemen, in the terror attack at an upscale cafe in Dhaka.
He was subsequently remanded to eight days' police custody twice.
Police detained another suspect, University of Toronto student Tahmid Hasib Khan, on August 3. Tahmid has not so far been shown as arrested for the attack.
