149. (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 144 or by an officer not below the rank of field officer duly authorised in this behalf by the authority or officer specified in section 144. (2) Where on such reconsideration by the officer authorised in this behalf under sub-section (1), it appears to him that the conduct of the offender since his conviction has been such as to justify a remission of the sentence, he shall refer the case to the authority or officer specified in section 144.