A local court had earlier granted custody of Chaudhary to NIA from March 11, to question him in connection with the Mecca Masjid blast case. He will remain in their custody for 15-days till March 26.
"Rajender Chaudhary's questioning is still on," NIA sources said today.
The NIA wanted to question Chaudhary for his alleged role in planting a bomb at Mecca Masjid and brought him to the city from Haryana on a transit warrant.
A cellphone controlled pipe bomb had gone off at the historic Mecca Masjid here during Friday prayers on May 18, 2007 killing nine persons. Five others were killed after police opened fire at a mob protesting the blast.