The True Patriot Love Foundation had reported the two plaques stolen from a Toronto overpass on Highway 401, saying they were taken down between December 2012 and February 2013.
But Toronto police Const. Wendy Drummond says an investigation has found that it was workers doing maintenance on the overpass who removed the plaques.
The 45- by 60-centimetre plaques have an image of people overlooking the Highway of Heroes as a soldier walks hand in hand with a child below a waving Canadian flag.
The Ontario government dedicated the stretch of Highway 401 between CFB Trenton and Toronto as the Highway of Heroes to honour soldiers killed during the mission in Afghanistan.
People regularly lined overpasses to pay respects as hearses passed by carrying the caskets of Canadian soldiers.