A few weeks ago my new mavic pro ND filters arrived so i thought i would try them out with a quick flight in my backyard. I never flew outside my property fence line and only max alt 25 Metres. One hour later two police arrive and say someone complained about my drone and also his bodycam was filming me. I explained I was allowed to fly in my own yard , not in a No fly zone and by law could go up to 120 M but i only flew at 20M. They wanted to see my footage but i declined. They took my details , also asked me if I was aware a preschool was nearby , so its likely a staff member assumed i was filming kids and called the police. It stressed me out for a day . Police emailed the next day saying I had nothing to worry about.