Back in the US it existed as far back as 1991. Back then I had a product called a K-40 "Chipsradar". What it did (aside from being a normal radar detector) was detect the handheld radio frequency of the CHP walkie-talkies (1-2 mile range) that linked up with the cars that relayed the transmissions to the station and used the signal strength as a proximity detector. It worked beautifully sniffing out speed traps since at the time CHP did not use radar all that much and would just hide on or behind overpasses looking for speeders.
It was exactly the same thing as the "Beartracker" you mention. That was also available back in the 1990's.