Why all the mystery surrounding the city where ABC's Rookie Blue is being filmed?

I have watched almost every episode and have yet to see any referance as to what city or country they are in. There are no markings on the police cars, uniform shoulder patches, license tags or signage to give any hint as to where they are. I have seen lapel pins on the police chiefs uniform which appear to be royal crowns which leads me to beleive they are somewhere in Canada. Any thoughts?