Sounds a little like DV202 in the lake at Peenemunde.

The Kölpensee; I was told about that whilst visiting Peenemunde years ago. At the little museum there, I can vaguely remember murky dive photos of the aircraft on the lake bed.

I also remember seeing the DTM Lanc section on the ground outside at the railway yard that’s part of the museum’s outside store not long after it was recovered. It’s quite a big chunk and the photos don’t really convey that at all. Because its missing the outer engine nacelle, at first glance I thought it was a Manchester.