(MONEY Magazine) – Confess and all will be forgiven--if, that is, you're willing to finger a sleazeball in, say, the Cayman Islands.

A new, one-time IRS program offers individuals using illegal offshore tax shelters amnesty from prosecution and civil fraud penalties if they are willing to name the promoters (and pay their own back taxes, interest and late penalties) by April 15. Tax cheats are advised to act: The IRS expects the promoters' client lists to lead investigators back to hundreds more individuals. In fact, recent court orders have allowed the IRS to check AmEx, Visa and MasterCard records for cards linked to offshore accounts, and some 1,000 cases are already being investigated. According to an IRS official, the names of well-known athletes and entertainers have already surfaced. --AMY WILSON