They were interrogated in connection to the September 13 serial blasts in Delhi, in which 25 people were killed and over 70 injured.

They Delhi Police team suspected that the two inmates, who are serving jail terms, possess vital information about a few activists of the Indian Mujahideen (IM) and Student Islamic Movement of India (SIMI), said a senior officer who was on duty when the Delhi Police team visited the jail.

Two officers of the Delhi Police — Inspector Hriday Bhushan and Sub-Inspector Umesh Barthwal — had interrogated Ansari and Happy at the chamber of Jail Superintendent Kumaresh Roy. First the gangsters were interrogated separately for two hours in Roy’s room and later, together for two hours, said an officer.

“Though the police didn’t disclose much about the duo’s association with IM and SIMI, the officers told us that the gangsters knew some of those who had set off the bomb at Karol Bagh,” he added.

Earlier, the Delhi Police had moved a petition at the chief metropolitan magistrate’s court in Delhi seeking an order to interrogate Ansari and Singh. The order was passed on October 10.

“The Delhi Police team came to Alipore Central Correctional Home on October 15 and produced the court order before the jail authorities. Accordingly, the interrogation was arranged at the jail superintendent’s chamber,” said the jail officer.

Recently, the Special Task Force of Kolkata police had interrogated Aftab and four of his fellow inmates in Alipore Jail regarding their connection with terror outfits and the underworld.