The above site covers the regulations for Canadian Whiskey. Section (v) states "be mashed, distilled and aged in Canada".
I've always thought Canadian whiskys, such as Crown Royal, blend in American made Straight whiskeys (straight bourbon or straight rye). The word was once going around that Diageo was sitting on lots of Stitzel Weller barrels that they used in Crown Royal. The above statement would imply this can not be true.
Of note, there is the additional statement of "(b) may contain caramel and flavouring.". Flavouring is not well defined and also not limited by a certain %. Who knows, the flavouring could be 99% of whiskey and as long as it meet other requirements then it could still be approved as Canadian whiskey???