previous leak around bathtub

lydriver

took the panel off the bath to look underneath as the sealer looks like it's been put on with a (brickies) trowel

there's obv been a problem in the past as there was a towel and plastic bag underneath but it's all dry now

should I be doing something about this mould? , stain? or whatever it is tho....it smells a bit but prob no more than any other area underneath a bath!

bluesnake

I'd spray with bleach a good few times. Then let it dry and paint it possibly with something that is oil or epoxy based, something to seal it in.