I've always thought it was someone known to the family but I personally don't think Andrew'a dad has any knowledge at all of what happened to him. I'm pretty sure that if your child goes missing and you have any knowledge at all about who he may have gone with you would tell the police and they would rule that person out or not. Listen to the interview he gave. The police were too busy investigating the family he felt they weren't looking for Andrew so felt if he wasn't around the police would shift focus to actually looking for Andrew. I'm sure he feels guilt, because he son vanished and he probably feels he should have notice or spotted something to indicate Andrew was about to ditch school and run off to London. I don't think for an instant second he has even a small inkling as to who is involved. It's a shame isn't it. That not all cases get equal limelight and attention. Endless media coverage when Maddy had been missing ten years. Let's hope the same happens for Andrew.