R (Stewart) v Managers of the NW London MH NHS Trust (1997) EWCA Civ 2201
From Mental Health Law Online
Part II (civil) and Part III (criminal) powers can co-exist and operate independently of each other. "If he were discharged by the tribunal it would be a discharge in relation to his liability to detention under Section 3 which would in no way affect the Secretary of State’s powers to recall him as a restricted patient"