No penalty on voluntary payment of duty prior to show cause notice; Expl. to sec. 11(2AB) is retrosp

Excise & Custom : Explanation 3 inserted in section 11A(2B) of Central Excise Act, 1944 by Finance Act, 2010 with effect from 8-5-2010, is a clarificatory provision having retrospective effect and, therefore, assessee making payment of duty voluntarily prior to issuance of show-cause notice may claim benefit thereof for prior periods as well