Saidapet Metropolitan Magistrate Saravanan declined to grant them bail.
The court sent Prashant, a key accused, to police custody for three days as sought by the Crime Branch-CID.
Meanwhile, Madras High Court today adjourned to May 29, hearing on an anticipatory bail application of Sanjay Kumar Bafna, who is on the look out by the CB-CID.
CB-CID would "in due course" move the court to take into custody Uttam C Jain and Jasraj Jain, who were arrested yesterday and are now in Puzhal prison, a police release said.