If any seaman engaged outside India is imprisoned for any offence for which he has been sentenced to imprisonment for a term not exceeding three months, and if, during such imprisonment and before his engagement is at an end, his services are required on board his ship, any magistrate may, at the request of the master or owner or his agent, cause the seaman to be conveyed on board the ship for the purpose of proceeding on the voyage or to be delivered to the master or any mate of the ship or to the owner or his agent to be by them so conveyed, notwithstanding that the period for which he was sentenced to imprisonment has not terminated.