Bar on prosecution prevents prosecution where wealth tax penalty has been reduced or waived, preserving related evidentiary admissibility. A bar on prosecution prevents proceeding for offences under sections 35A or 35D where the penalty under clause (iii) of section 18(1) has been reduced or waived by an order under section 18B for the relevant assessment year. Separately, statements, accounts and other documents produced by a person before a wealth tax authority (not an Inspector of Income tax) are not inadmissible merely because they were made or produced in the belief that penalty reduction or waiver under section 18B or compounding would follow.