Here's your proof that he is an accomplice/ assisting a criminal act.
This i believe is chargeable offense.

If you are seriously certain that he is refunding as you said, send proof of such an act and ask the respective victims to acknowledge it, as no one here can trust words of a conman or a person claimed to be the brother as such.

on a side note, returning the funds is a start but he must come here and apologize by himself for bringing such frustration and distress to many forumers here else i'm sure the police charges won't be dropped.