The judicial custody of a Delhi High Court blast accused Wasim Akram Malik was extended for two more weeks by a city court.
Special NIA Judge H S Sharma extended Malik's judicial custody till January 31 in an in-camera proceeding after he was produced before him.
Meanwhile, according to court sources, the judge also allowed National Investigation Agency's plea to secure the handwriting specimens of Malik, a student of Unani medicine in Bangladesh.
Malik was then produced before a metropolitan magistrate who took his handwriting samples to be sent to the experts for examination.
Another co-accused Amir Abbas Dev, lodged in Tihar Jail, had been produced before the court on Monday and remanded to judicial custody till January 30.
The probe agency has dubbed Malik as a 'key link' in the conspiracy behind the blast outside gate number 5 of the High Court which killed 17 persons and injured over 90.
Dev, a Jammu and Kashmir native, was arrested by the NIA for allegedly sending terror e-mails to media groups after the September 7 blast last year.