Mold not disclosed by seller on rental duplex

[Matt Schambeau]

I purchased a duplex (two 2/1 units) in Roswell, GA in July of 2017.  I recently went into the property and the tenant showed me a bunch of mold growing on the inside of the bedroom walls around the North perimeter of the house (two bedrooms) from the floor to about knee high.  The unit has a roof less than a year old and all windows have been sealed well.  It was built in 1962.  

In speaking with the tenants with a translator (they do not speak English), they told me that the previous owner new about it and it had been an issue for many years.  These tenants have lived in the property for over 10 years.  They even told me that the old owner used to pay them to clean the mold off the walls.  They also stated that it is only really an issue in the winter.  In the summer it goes away. It is my understanding that the seller has a legal obligation to disclose this to buyer if he is aware of it.  Is that correct?

I had two mold remediation companies come and look at it and they both said it is due to the temperature variance in the winter from the craw space to the bedroom.  There is no insulation on the floor and the vapor barrier also does not go all the way to the exterior of the house on the side with the issue.  I have not received the quotes yet on the cost for the remediation.

I spoke with my realtor who advised I speak to an attorney, but said the seller has deniability because he did not live in the unit so therefore would not know.  I spoke with another realtor that said my realtor and brokerage should start the conversation with the seller.  My realtor disagreed.  Any feedback on this would be greatly appreciated.  Also if anyone has a referral on an attorney in the Atlanta, Georgia area...that would be great.  This is my for rental property, so I'm just figuring things out.  Thanks for your help!