In the remand petition, investigation officer of the Criminal Investigation Department (CID) said he took up the investigation charge on August 30 and he would require time for interrogation to find out the motive.

The defence lawyers submitted a petition seeking bail and cancellation of the five-day remand prayer. Moving the petition, Advocate Gyanendra Chandra Biswas told the court that Dhanmondi Police had earlier taken Partha on a four-day remand and he was sent to jail after completion of another two-day remand.

Moreover, Partha was physically and mentally tortured in custody of law-enforcement agencies for a five-day confinement without court order. Life of the young man will be at risk if he is remanded again, as he cannot move without the help of others, the lawyers argued.

After hearing both sides, Metropolitan Magistrate Jahangir Alam rejected the bail petition and placed Partha on a three-day remand.

Intelligence agents picked Partha on August 25 from Heart.net Cyber Café at the Elephant Road.

The intelligence agents quizzed him in an undisclosed place for five days, sidestepping the law to produce arrestees before court within 24 hours of arrest.

Partha is facing charges of emailing the Bangla daily to claim the responsibility for the August 21 grenade attack that killed 19 people and threatening to kill Hasina in seven days.

The lawyer said Partha completed his Master's in business administration at Chennai in India and returned to Bangladesh in July, adding that he was browsing websites for jobs.