The Ombudsman is investigating the way three government departments have treated Ahmed Zaoui.
The Algerian refugee has been in custody since arriving in New Zealand in late 2002, after the Security Intelligence Service said he posed a security threat.
An investigation by Anand Satyanand began in October after a complaint by Zaoui's lawyers.
Satyanand is looking into the Corrections Department's contact with police, the reasons for Zaoui's initial placement in Auckland's maximum security prison, Paremoremo, and his treatment there. Satyanand says his investigation will be completed within the next few weeks.
Alliance MP Matt Robson says Customs and the Immigration Service are also being investigated. And he says he has laid a further complaint with the Police Complaints Authority alleging Zaoui was illegally detained.
Robson says he also wanted the Security Intelligence Service investigated, but the Ombudsman has no legal jurisdiction to do so.
Zaoui was transferred to Auckland Central Remand Prison in October, after the Corrections Department decided he no longer posed a high security risk.
