Shauman Haq, 27, was arrested near Vikas Marg yesterday following a tip-off by Delhi Police's Special Cell, an official said.
Haq was later produced before Additional Sessions Judge Sidharth Sharma who handed over his custody to the special cell of Delhi police after the probe agency said he was required for custodial interrogation to unearth the larger conspiracy. Haq will remain in police custody till September 30.
The police told the court that Haq was required to be confronted with various "incriminating" evidence recovered in the matter and to gather information on the other accused.
On August 9, the Special Cell had arrested 29-year-old Syed Mohammed Zishan Ali after he was deported from Saudi Arabia.
On August 1, 25-year-old Raja-ul-Ahmed was arrested following a tip-off from the West Bengal Police.