11(1)A person required to be detained under an interim custody order or a detention order may be detained in a prison or in some other place approved for the purposes of this paragraph by the Secretary of State.
(2)A person for the time being having custody of a person required to be detained as aforesaid shall have all the powers, authorities, protection and privileges of a constable.
(3)Subject to any directions of the Secretary of State, a person required to be detained as aforesaid shall be treated as nearly as may be as if he were a prisoner detained in a prison on remand and any power of temporary removal for judicial, medical or other purposes shall apply accordingly.
(4)A person required to be detained as aforesaid who is unlawfully at large may be arrested without warrant by any constable or any member of Her Majesty’s forces on duty.