A Delhi court on Thursday sent Yasir Ahmad Dar, the ninth person arrested in the Red Fort blast case, to NIA custody till December 26.
Special Judge Prashant Sharma allowed the plea of the National Investigation Agency (NIA) seeking custodial interrogation of the accused.
Earlier in the day, the NIA arrested Dar, a Jammu and Kashmir resident, allegedly a close associate of suicide bomber Umar-un-Nabi.
Dar allegedly played an active role in the conspiracy behind the blast that claimed 15 lives and left many others injured on November 10, the NIA said.
An active participant in the conspiracy, Dar had allegedly taken an oath to carry out self-sacrificial operations, the agency said.
It said Dar was in close contact with the other accused persons in the case, including Umar-un-Nabi and Mufti Irfan.