This section applies where a prisoner custody officer who performs custodial duties at a contracted out prison is responsible for the custody of a prisoner who is outside the prison for temporary purposes.
For the purposes of such prison rules as relate to breaches of discipline the prisoner shall be deemed to have been in the custody of the director of the prison at all times during the period for which the prisoner custody officer was so responsible, and that officer may bring a charge of breach of such rules as so relate against the prisoner in respect of any such time.
Nothing in subsection (1) above shall render a prisoner liable to be punished under prison rules for any act or omission of his for which he has already been punished by a court.