Two criminal investigations launched by military police into the actions of Canadian special forces soldiers in Afghanistan probed the alleged improper killing of Afghans, CBC News has learned. 

Military sources said that the first investigation, called Sand Trap 1, resulted in no charges being laid against any Canadian soldiers. 

But the second investigation, called Sand Trap 2, seems to suggest another nation may have been involved in the alleged improper killing being investigated. 

A briefing note written for Defence Minister Peter MacKay and obtained by CBC News also appears to point in this direction. It talks about military police talking with military lawyers to discuss "jurisdiction" and "liaison."

afghanprobeat300

Canadian soldiers patrol early morning Saturday outside Salavat, southwest of Kandahar, Afghanistan. (Anja Niedringhaus/Associated Press)

Throughout the Afghan engagement Canadian special forces operated jointly with those of other nations, including Afghanistan and the U.S.

On Monday, CBC News revealed  that Canada's Defence Department quietly began a major inquiry in 2008 into the military's highly secretive force known as Joint Task Force 2, or JTF2.

The military investigation began after a member of JTF2 raised serious allegations against another member of the force and the force in general relating to events that happened between 2005 and 2008.

That investigation, called Sand Trap 1, ended after a year and a half with no charges but sparked a second, wider criminal investigation into broader issues called Sand Trap 2, which is still going on.

In addition, a military board of inquiry, which investigates major problems within the Canadian Forces, is looking into administrative and non-criminal issues surrounding the case, and is hearing 100 witnesses as it conducts its probe.

Rear-Admiral Robert Davidson of the Canadian Forces acknowledged in a statement that Sand Trap 1 "identified other matters that warranted a second investigation," known as Sand Trap 2, which is still ongoing.

"Any speculation about these matters while investigative processes are ongoing is unhelpful and may taint the environment in which the investigation is taking place," said Davidson, who is director of staff for the Strategic Joint Staff.  

With files from James Cudmore