Mamu, who was on his way to Saudi Arabia for lesser Hajj, was detained at Cairo International Airport before being repatriated back to Nigeria.
Meanwhile, the DSS, in the affidavit in support of the ex-parte motion, alleged that its preliminary investigation established the offences of logistics supplier, aiding and abetting acts of terrorism against Mamu.
The security outfit, in the affidavit deposed to by Hamza Pandogari, a legal officer with the service, said it was necessary for Mamu to be detained for 60 days pending the conclusion of the investigation of various acts of terrorism against him.
It alleged that the investigation established an act of terrorism financing against the former terrorists’ negotiator.
It alleged that Mamu, “the self-acclaimed Kaduna train negotiator exploited the opportunity to perpetrate, aid and abet as well as render support to both local and international terrorist organisations,” among others.
The DSS had warned Nigerians over making comments on its arrest of Mamu.
The DSS, in a statement by its Spokesman, Peter Afunaya, asked the public to leave the agency alone and allow it to concentrate on the investigations which it said the outcomes had been “mindboggling.”
This came hours after the Islamic cleric, Sheik Gumi, to whom Mamu is an aide, had faulted the arrest of the negotiator.
Gumi, at a religious gathering on Friday in Kaduna, had asked the security agency to charge Mamu to court if it had any evidence against him, rather than keeping him in custody.