This happens now if you use the same piece of cling film or foil to wrap it in. Should use a fresh piece every time the piece of cheese is opened, so said a chef on TV.
Fresh piece of foil or cling film? Hah! Wouldn't take too much notice of TV chefs on that - haven't you noticed that they always use a fresh (i.e. brand new) pot or pan for everything they cook? Never anything that looks a bit black or that might have seen the close attentions of a brillo pad at some point. In the REAL world - just cut the mould off!