The State Security Services (SSS) Thursday morning raided the residence and office of Tukur Mamu, following his arrest at the Aminu Kano International Airport on Wednesday.
Mr Mamu, a newspaper publisher, negotiated the release of some of the hostages in the March 2022 train abduction in Kaduna.
Mr Mamu was earlier arrested by Interpol in Egypt on his way to lesser Hajj in Saudi Arabia. He was forced to return home to face further questioning by Nigerian authorities.
Meanwhile, it was learnt that some armed security operatives raided his house and office at about 12:30 a.m.
Sources disclosed that the operatives seized phones and laptop computers found at the premises, adding that Mr Mamu’ s wives who were travelling with him to Saudi Arabia have been released. However, his son, Ibrahim, and son-in-law Faisal, are still being held by security operatives.
The Management of Desert Herald Newspaper had in a statement on Wednesday condemned the arrest and demanded the immediate and unconditional release of its publisher.
Several weeks ago, Mr Mamu withdrew as the lead negotiator in securing the release of the hostages of the Kaduna train abduction. He accused the Nigerian government of threatening his life.
The terrorists who carried out the train attack are still holding on to some of the passengers.