The Bihar police said it would take custody of the arrested Indian Mujahideen (IM) chief Tehseen Akhtar alias Monu.
Tehseen Akhtar is one of the most wanted terrorist blamed for a number of terror attacks including last year's serial bomb blasts at BJP's Prime Ministerial candidate Narendra Modi's Patna rally.
"We are preparing papers to seek custody of Tehseen Akhtar alias Monu in connection with a case registered with Gandhi Maidan police station related to serial blasts at a rally in Patna on October 27 last year," Anti-Terrorist Squad (ATS) IGP Paresh Saxena said.
"Legally, we are bound to take his custody in connection with Gandhi Maidan case," he said.
Tehseen Akhtar was arrested on Tuesday by the Special Cell of Delhi Police.
The arrest of Akhtar come days after Delhi Police nabbed another another top IM operative Zia Ur Rehman alias Waqas from Ajmer in Rajasthan along with three of his associates.
Tehseen Akhtar, who hails from Maniyari village of Bihar's Samastipur district is considered the "mastermind" of multiple explosions at Modi's Patna rally that had killed eight persons including a terrorist.
Meanwhile, a Samastipur report said that an eerie silence prevailed in Maniyari under Kalyanpur police station, about 16-km from Samastipur district headquarters.
Nobody in Maniyari was willing to talk on the issue and when contacted Akhtar's uncle Takki Akhtar, also a JD(U) leader, said that he has already clarified that he and his family has no contact with IM operative's family.