(9) Any amount deposited by way of security under sub- section (8) may, at any time, be forfeited in whole or in part by the State Transport Authority if it is satisfied after making such inquiry as it thinks fit that-
(a) the permit was obtained by fraud or misrepresentation, or
(b) the holder of the permit has failed without reasonable cause to use the vehicle or vehicles for the purpose for which the permit was granted, or
(c) the holder of the permit has committed a breach of any condition of the permit, or
(d) the holder of the permit has used or caused it to be used in any manner not authorised by the permit: Provided that no such forfeiture shall be made unless the State Transport Authority has given the permit- holder a reasonable oppor- tunity of being heard.