Sheikh Ibrahim Zakzaky was arrested after deadly clashes killed almost 350 of his followers.
The country's Shiite minority has had several high-profile conflicts with Nigerian security forces.
Kaduna's state government declared the Islamic Movement in Nigeria to be unlawful on Friday.
More than 300 people were reportedly killed in December's clashes between Shiites and the army.
Nigerian Shiites clashed with the army in December, with 300 sect members reportedly killed.
The Shiite leader has been detained since December, when soldiers clashed with Shiite sect members.