Sch 2 para 2A
(1) This paragraph applies to a person who has arrived in the United Kingdom with leave to enter which is in force but which was given to him before his arrival. (2) He may be examined by an immigration officer for the purpose of establishing— (a) whether there has been such a change in the circumstances of his case, since that leave was given, that it should be cancelled; (b) whether that leave was obtained as a result of false information given by him or his failure to disclose material facts; or (c) whether there are medical grounds on which that leave should be cancelled. (2A) Where the person’s leave to enter derives, by virtue of section 3A(3), from an entry clearance, he may also be examined by an immigration officer for the purpose of establishing whether the leave should be cancelled on the grounds that the person’s purpose in arriving in the United Kingdom is different from the purpose specified in the entry clearance. (3) He may also be examined by an immigration officer for the purpose of determining whether it would be conducive to the public good for that leave to be cancelled. (4) He may also be examined by a medical inspector or by any qualified person carrying out a test or examination required by a medical inspector. (5) A person examined under this paragraph may be required by the officer or inspector to submit to further examination. (6) A requirement under sub-paragraph (5) does not prevent a person who arrives— (a) as a transit passenger, (b) as a member of the crew of a ship or aircraft, or (c) for the purpose of joining a ship or aircraft as a member of the crew, from leaving by his intended ship or aircraft. (7) An immigration officer examining a person under this paragraph may by notice suspend his leave to enter until the examination is completed. (8) An immigration officer may, on the completion of any examination of a person under this paragraph, cancel his leave to enter. (9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (10) A requirement imposed under sub-paragraph (5) and a notice given under sub-paragraph (7) must be in writing.