Drone testing in UK or UFO?

Just recently read about some sightings of a Cessna type light aircraft following a dark dome shaped flying object. On one occasion this was observed near Cardington on 4th september and again on 2nd september in vicinity of Isle of Sheppey. Now this was on the UK-UFO site but since the reports were so similar and aviation related I was wondering if any-one would have an idea what it was. I know that the police use drones, but wasn’t sure if they controll them in flight from aircraft like for instance the Diamond DA42NG Twinstar. Is there a lot of surveillance drone testing going on with forces around the country? Could this explain some of the (wince) “ufo” sightings around Stansted recently?

Martin