(1) A direction under section 70 shall cease to have effect at the expiry of the period specified in the direction unless -
(a) it has previously ceased to have effect, or
(b) it is continued in force by a further direction.
(2) The specified period shall not end after the end of the period of two months beginning with the date of the direction.
(3) Where -
(a) a person is held in custody in a prison or other place by virtue of a direction, and
(b) the direction ceases to have effect (whether or not by reason of the expiry or cesser of section 70),
it shall be lawful for him to continue to be held in custody in that prison or place until arrangements can be made for him to be held in custody in accordance with the law then applicable to his case.
(4) Nothing in subsection (3) shall be taken as permitting the holding in custody of a person who is entitled to be released from custody.