(1) Where a sentence has been suspended, the case may at any time, and shall at intervals of not more than four months, be reconsidered by the authority or officer specified in section 152 or by any officer not below the rank of a Deputy Inspector-General duly authorised by the authority or officer specified in section 152.
     (2) Where on such reconsideration by the officer so authorised it appears to him that the conduct of offender since his conviction has been such as to justify a remission of the sentence, he shall refer the matter to the authority or officer specified in section 150.