In 2010, Canada Revenue Agency auditors unearthed a scheme they called a sham that ultra-rich Canadians were using to dodge taxes. But previously unreported court records obtained by CBCs The Fifth Estate and Radio-Canadas Enqute show it didn't stop then. Some taxpayers continued to exploit the tax dodge for several years without officials realizing.

Numerous internal emails filed in court this summer reveal involvement of Caleb and Tom Chan in a KPMG offshore scheme so secret, neither Canadian tax collectors nor even their spouses were ever supposed to find out.