Section 221(1)(c) in Siliguri Municipal Corporation Act, 1990
(c)that any material alteration of, or addition to, any building has been commenced or is being carried on or has been completed in contravention of any provision of this Act or the rules or the bye-laws made thereunder, it may after giving the owner of the building a reasonable opportunity of being heard, make an order directing that such erection, alteration, addition or projection, as the case may be, or so much thereof as has been executed unlawfully or such building or existing structure be demolished or altered and upon such order it shall be the duty of the owner to cause such demolition or alteration to the satisfaction of the Mayor-in-Council within such period as may be fixed in this behalf and in default, the same may be demolished or altered by the Mayor-in-Council at the expenses of the said owner.