If you were not the owner, then what probably happened is the owner sold the home, and gave you some of the proceeds. That's not a taxable even to you, and it doesn't matter from a tax or law point of view, what the giver did to get the money that they gave to you.
If you are concerned that you might have been a part owner, and part of the gain (profit) from the sale is taxable to you, you should start by seeing an attorney to review the deed and other documents of sale, to clarify your position.
