Suhaib Pottanikkal, accused in the 2008 Ahmedabad serial blasts case was arrested by the Crime Branch from Kerala on 24 may.
Earlier, the Gujarat police arrested the suspected mastermind in the case, Mufti Abu Bashir, along with nine others, in connection to the bombings.
The 2008 Ahmedabad bombings were a series of 21 bomb blasts that hit Ahmedabad on July 26, 2008, within a span of 70 minutes.
56 people were killed by the bombing and over 200 people were injured.
Islamic militant group Harkat-ul-Jihad-al-Islami had claimed responsibility for the attacks.