Bankruptcy alone does not relinquish ownership of the property. The bank has to legally foreclosure on the investor in order to take back the property. This means the investor could actually keep collecting any rents received until the property is sold at auction assuming the bank does not assume the rents as they are entitled to. The main thing bankruptcy accomplishes is that it eliminates the right of the lender to collect a deficiency judgment from the investor when the property sells for less than its loan amount.