(a)any power exercisable by the Board under this Act shall be exercisable also by [a [Chief Commissioner of Customs] [Inserted by Act 29 of 1988, Section 7 (w.e.f. 1.7.1988). ] or a [Commissioner of Customs] [ Substituted by Act 22 of 1995, Section 50, for " Collector of Customs" (w.e.f. 26.5.1995).] empowered in this behalf by the Central Government;