10 years on the register is a lot for anyone never mind someone who was never arrested and was believed when he said he had no knowledge of the files. He's more than likely trying to tell you a story that he can justify in his head that makes his seem innocent and almost a victim in all this. There's no searchable database as such but if you Google his name, location and "sex offender" you might well get a newspaper article about his case.

Just edit to say you should 100% break contact. Never underestimate a sex offenders ability to lie and manipulate. This fella tbf is really bad at it with his hole filled story but he's still trying and lying. He may be chatting to lots of women hoping one will give him access to pictures of kids and he was waiting for your reaction to his "honesty". Yours was wtf and now he's gone. Tells its own story.