Any person who, having been sentenced to imprisonment, . . . F4F5custody for life or youth custodyor ordered to be detained in a detention centre F6or a young offenders institution, or having been committed to a prison or remand centre, is unlawfully at large, may be arrested by a constable without warrant and taken to the place in which he is required in accordance with law to be detained.

The provisions of the last preceding subsection shall apply to a person who is detained in custody in default of payment of any sum of money as if he were sentenced to imprisonment.

For the purposes of this section a person who, after being temporarily released in pursuance of rules made under subsection (5) of section forty–seven of this Act, is at large at any time during the period for which he is liable to be detained in pursuance of his sentence shall be deemed to be unlawfully at large if the period for which he was temporarily released has expired or if an order recalling him has been made by the F13Secretary of Statein pursuance of the rules.