Just because a newly returns CBI officers thinks that another CBI officer murdered his wife, Arshad Warsi goes straight to jail, prisoner clothes and all. Means No warrant / No court hearing and then No police questioning (if it is assumed that he was in remand). And later when his help was required, initially it was told that he can't move out of Jail but later shown that he was meeting folks in CBI HQ and meeting with NIA head etc.