Great info/clean-up tips FEMA:
FEMA: Clean Now To Prevent Mold And Mildew
We had a major flood where I live in 97'. One of the things you can do is mix a small amount of bleach (1 1/2 c w/ gal water) and spray the mold area. Also, make sure you wash the floor. The FEMA link has some good sanitizing/drying tips. Remember to hit all the mold, as mold does grow. And, removing sheet rock is critical, those directions are
also in the link.
STT suggested a heater, that will help and also add an oscillating fan at the same time. We actually had to spray repeatedly on the wooden beams, as it does take sometimes mth to dry out properly. If you had a leak....how much water was standing before you got it fixed? The area that had water can wick up on the wood..i.e. wooden framing, etc. Spray that w/ the bleach treatment. I also use a product for cleaning that kills 99.9 percent germs incl. HIV. I purchase this at Sam's club...OdoBan it works great for cleaning. If these things don't help contact health dept or have professionals guide you or your LL. If you like the rental, you can shape it back up.