Basically I have a friend who lives next to a man who physically and mentally abuses his fiancee. She wants to inform the police, but they have no proof and the victim is too scared to admit it so she lies and says everything is fine. She mentioned recording the argument, where she could physically hear her being beaten. She has no ideas on the rules in the UK about using this as evidence. I know privacy laws are different from the US, but can this be taken to the police as evidence? Or would it be thrown out?