While some wealthy U.S. citizens have recently come under scrutiny after their names emerged in files leaked from a leading offshore law firm, another tax scandal has surfaced in Canada involving global accounting and legal giants KPMG and Dentons, respectively.

The Canadian Broadcasting Corp. reported Wednesday that former top Canadian firm Frasner Milner Casgrain (FMC), which three years ago was absorbed into Dentons, inked a 17-page “opinion” letter back in 1999 that “endorsed” a tax shelter operated by KPMG on the Isle of Man, a tiny self-governing U.K. protectorate in the Irish Sea.