Accepting plea of the Patna police, Judicial Magistrate Prabal Dutta granted seven-day police custody of Nyaz for intensive questioning on the blasts that killed six persons at the venue of Narendra Modi's rally on Sunday.
Nyaz, an associate of Indian Mujahideen operative and serial blasts' accused Imtiyaz Ansari, was formally arrested on October 30 after being initially detained for questioning.
He was picked up by the police on October 29 from Alaula village in East Champaran district.
A day later, he had been sent to 14 day judicial custody by the same court.
The two others arrested were Imtiaz Ansari and Ainul alias Tarique who were caught from the Patna railway platform toilet.
Tarique died at Indira Gandhi Institute of Medical Science late last night.