Firstly I apologise for my English as I am not a native, once I was in the UK for an exchange program at university and I am from East Europe. I will try to keep it short and explain my problem. I was once with a girl from my home country and she had real feelings for me, so did I but I was bad with her. I cheated on her a lot because I was addicted to it and feeling of lust. I even flirted with her sister and once we kissed after alcohol, so you see the problem. She said this should never happen again due to the situation. I can't justify my behavior.
Then my gf (now ex) came to see me in UK. Honestly it was so nice and I didn't know then she had figured my old phone password at my grandmother's as her behavior was same. Later her brother and 2 friends came and we hired a car to go camping to some national forest. This is where the horror story begins. I was sedated with drinks, tied up and beaten badly including cigarette burns and cuts with a knife. My gf was crazily crying saying she loved me but also hurting me, telling me to tell her every damn detail and why. I felt I was going to die and the boys told me this is it. 2 hours later when they weren't watching I tried to grab my phone even though I was so broken and tied but they smashed it hard.
My gf said let me live as I'm still breathing and let me heal as she saw how bad it was. In the end they decided to let it be as long as I don't ever tell anyone or they can cause more problems in our home country. But here I also know how to deal with things but I agreed to forget it all. If it wasn't my gf and their sister (who randomly called and had no idea this was happening), it may have been worse. I told her everything but kept her sister out of it as I thought she may even hurt her. They took me home a day later and I never treated anything unlike I got to EE 2 weeks later. I had some fractures and my ex gf was in contact throughout and worried for me. It's obvious she loves me still.
Now the problem is I am with a new girl back in my home country, we are happy, faithful, we shared our lives so I told her what happened thinking I needed to let it out. She said she will go to the cops here in EE (won't mention country as prefer anonymity) if I don't and she's being aggressive about it. But the incident didn't happen here and if I don't say anything to the cops, nothing happens? Or will they contact UK cops? I don't want anything to affect my ex or her career, we still talk.