My Miele K1642 fridge has drips and puddles of water on the inside?

Miele fridge, about 6 years old. Over the last 9 months it has started dripping on the inside, making packaging soggy, dripping into and onto pots of yoghourt, bacon etc...but the back of the fridge has ice all over it. Turning temperature up and down is useless. The seal is bit dodgy, the freezer part is working fine. Deeply fed up with getting packets out which have a layer of water on the top. This can't be right. Any answers?