Ahmedabad, Aug. 20: Sleuths probing the Ahmedabad blasts today claimed “substantial evidence” of student outfit Simi’s role, a day after saying Mufti Abu Basheer had owned up to the attacks.

Much of the proof — CDs, DVDs and arms — had been unearthed from the Vadodara house of an uncle of Usman Agarbattiwala, one of the 10 accused in custody, sources said.

They said 19 disks, with speeches of Osama bin Laden, were found in a bag and sent for forensic authentication.

In Karnataka’s Bijapur, two cousins, a dentist and a visa agent, both suspected to be part of the Simi group allegedly behind the Ahmedabad blasts, were arrested last night.