Jacqueline is right... If they knew. You must have hard proof that they deliberately and intentionally withheld that information.
Our Georgia contracts have been changed several times over the last few years. Proof of condition was the responsibilty of Seller. Sellers were required to provide buyer with any back-ground information and known current conditions in an attachment to the contract called the Seller's Disclosure Statement. Also property survey and termite letters, these are no long provided. Buyers were finding this practice to be a conflict of interest. The currently Georgia Association of Realtors (GAR) forms or standard contracts are written to in a way as to place responsibility in the hands of the buyer. This is called the "due diligent period". Unless you opt to purchase the property "as-is" meaning with all faults. Bank owned properties can't not provide Seller's Disclosure Statements since they have no knowledge of condition.
As for the mold, there are thousands of different types of mold and only a few are considered toxic. You can have a specialist to perform a remediation. In most cases, a good washing with soap and water then treat area with Clorox bleach often prevents its return. Although it will continue to return if you don't fix the source of moisture or leak in the first place.
I hope this helped. Good Luck
Robin Lanese, Realtor, ABR, CRC
Solid Source Reatly