As you are involved in this, be prepared to hear from the victim that you are a bad person, that you are responsible, and that you no longer are allowed to do things that might get the actual abuser in trouble. My experience was that it works (elder abuse) because the person is often still cognizant enough to be played, but not really making good decisions. Oh mom, they're going to put ME in jail and it's all cousin ______ s fault! It's hurtful, but do not follow their instructions, stay involved, even if you have to involve other parties, like the law.
Yes, we do need more information. Did your aunt incur this bad debt in her name or did she just give this person money and now he has bad debt in his own name?