Canadian troops and police were trained for two years by the international security contractor formerly known as Blackwater without the permission of the U.S. State Department.
The revelation is contained in U.S. federal court records, unsealed in North Carolina as part of a $7.5 million settlement of criminal charges against the company now called Academi LLC.
The Harper government has had a standing contract with the company since 2008.
It's paid millions of dollars going back to 2006 for the specialized training, given to special forces troops and some police officers.
U.S. prosecutors say Blackwater didn't seek the permission required under American arms control laws for the instruction, which took place between 2006 and 2008 and included training in marksmanship, defensive driving, bodyguard and close combat skills. National Defence and the government have over the years defended their association with Blackwater, which had been accused of killing civilians in Iraq, by saying that the instruction was necessary and unavailable anywhere else.