(1)A magistrates' court that has power to commit to prison a person in default of payment of a sum adjudged to be paid by a summary conviction, or would have that power but for section 82 or 88 above, may issue a warrant for his detention in a police station, and, if it does so, shall not, where it has power to commit him to prison, exercise that power.
(2)A warrant under this section, unless the sum adjudged to be paid by the conviction is sooner paid.—
(a)shall authorise any police constable to arrest the defaulter and take him to a police station, and
(b)shall require the officer in charge of the station to detain him there until 8 o'clock in the morning of the day following that on which he is arrested, or, if he is arrested between midnight and 8 o'clock in the morning, until 8 o'clock in the morning of the day on which he is arrested.
(3)Notwithstanding subsection (2)(b) above, the officer may release the defaulter at any time within 4 hours before 8 o'clock in the morning if the officer thinks it expedient to do so in order to enable him to go to his work or for any other reason appearing to the officer to be sufficient.