13. Notwithstanding anything contained in the foregoing sections, any licensing authority or any other prescribed authority may at any time revoke a driving licence, or may require, as a condition of continuing to hold such driving licence, the holder thereof to furnish a fresh medical certificate in ÔÇÿForm C' as set forth in the First Schedule, signed as required by sub section (3) of section 7, if the licensing authority has reasonable grounds to believe that holder of the driving licence is, by virtue of any disease or disability, unfit to drive a motor vehicle; and where the authority revoking the driving licence is not the authority which issued the same, it shall intimate the fact of revocation to the authority which issued that driving licence.