You should, of course call your closing attorney to review this situation.
But my opinion, there is not too much you can do as you can do.. Maybe the seller did not cover up what happened, maybe it happened before they were there..You may have some recourse with the home inspector, but there are usually statements ins their contracts that provide coverage for them too.
What was "covered up?" How did you find this.. Was something hidden? Or fixed?.. Just not to your liking.
Either way, you should contact your attorney that closed the property.
Your options are first to determine if you have been wronged and suffered a loss or about to suffer a loss because any potential fraud or failure to disclose. If so then collect your closing documents, contact the parties who were a part of your transaction and they should direct you on the course of action you may take.
All the best to you.