Court held that the provision for imposition of interest is a substantive provision. It is settled law that in the absence of any express words used in the provision making levy of interest retrospective, it can only be prospective, i. e., from the date on which it came into force. A reading of the provisions of section 234D of the Income-tax Act, 1961 , makes it clear that there is no indication in the language employed in the entire section that Parliament intended to make this levy of tax on excess refund retrospectively. On the contrary, after inserting this provision in the Act, it is specifically stated that it comes into effect from June 1, 2003. .( AY. 2000-01 to 2002-03)