Gas pipe

Many years ago I had an old gas fire removed and we just placed a modern electric fire in front of it. Recently I've had the opening bricked up however I now have a pipe coming out of the wall/ skirting. It doesnt appear to be capped, looks like black tape. I have concrete floors so it runs behind the skirting. How do I tell if it's a live pipe? And what trade do I use to remove it? Thanks