You are doing the right thing by setting your rent money aside, but you may end up not finding anyone to pay. If you walk away from the unit, continue to hold the money in an account and discuss your situation with an attorney if you ever hear from anyone about payment of rent.
Your lease is a contract, and it sets forth what you are required to do, and what the other party (the landlord) is required to do in return. You have an unusual situation, to say the least. No more can be required of you than what is in the lease, but as you may have anticipated, someone can pop up one day and (a) demand the rent money, or (b) demand something else of you that may or may not be within what you have agreed to by leasing the condo.
It sounds like you have a good instinct to try to get the matter resolved before you leave, so that no quesiton can be later raised. It may be tempting to just walk out (as you may, indeed, be entitled to do). But if yo prefer to be on the safe side and make sure there are no loose ends, there are ways to find out who owns the condo and some simple precautions you can take to make sure that when you do leave, no uncertainties will be following you out the door.
Answering this question does not set up a attorney-client relationship between us. My comments do not constitute legal advice. If you would like to pursue representation, please contact me.