UK ufo sighted by police officers

I’ve always been a sceptic when it comes to UFOs as I just don’t think there’s enough information to make an informed decision, however I was recently talking to my grandfather about it and he said that his brother in law who was in the police force in Northern England, he said that either him or another officer was driving when they saw a ufo in the sky, they followed the ufo before it shot off. When they got back to the station, they phoned the local RAF base to enquire about any planes flying over the area and were told that there were no planes flying at the time. I don’t have much more information on the case and will ask my grandfather more about it, but I would presume that it was probably in the 70s or 80s based on the age of my grandfather’s brother in law. My grandfather also told me about his teacher who flew in the RAF during WW2, who said they sighted a cigar shaped UFO. My grandfather is a very rational and level-headed man, and I know he wouldn’t make things like this up. It hasn’t really changed my perspective on whether these are extra terrestrial craft, but I do think there is something going on.