40.— (1) A prisoner who—

(a) is absent from a prison pursuant to an order under section 39 or another enactment or an order of a court, or

(b) is being brought to or from a prison or court,

may be placed in the custody of a prison officer, a prisoner custody officer or a member of the Garda Síochána.

(2) A prisoner in such custody is deemed to be in lawful custody.