On betrayal

I have recently had a bad experience. A partner of mine for 5 years, someone I trusted and liked, betrayed me by stealing €45,000 euro from my corporate bank account. He could do this because I gave him open access to my accounts as he did some banking and admin for me. He sent bogus invoices to our accountants without my knowledge and helped himself to the funds every month for over 2 years. This man is public school and Oxbridge educated, his need for money must have indeed been severe to betray me like that. Words fail me to describe how much I loathe this person. Go to lawyers you say? Well I did but the guy has no assets whatsoever. No house no nothing, so even if I did spend £50K taking him to court and getting a judgement, I would not be able to collect from him. So, now he hides behind his lawyer basically thumbing his nose at me. He currently works for someone I introduced him to tin the past. Of course this guy does not want to know that he has a cheap low crook working for him so nothing I can do there. Please if anyone has any ideas, I would love to hear them! Thanks