(1) A suspected international terrorist may be detained under a provision specified in subsection (2) despite the fact that his removal or departure from the United Kingdom is prevented (whether temporarily or indefinitely) by-
(a) a point of law which wholly or partly relates to an international agreement, or
(b) a practical consideration.
(2) The provisions mentioned in subsection (1) are-
(a) paragraph 16 of Schedule 2 to the Immigration Act 1971 (c. 77) (detention of persons liable to examination or removal)
(b) paragraph 2 of Schedule 3 to that Act (detention pending deportation), and
(c) section 62 of the Nationality, Immigration and Asylum Act 2002 (detention by Secretary of State).