Hello Rainer, thanks for your comments.
1. We know that the HMS Seraph transported the corpse of William Martin to Huelva (Spain). In the log war of this submarine, it doesn´t appear anything about a corpse.
2. Adolf Clauss was the German intelligence chief in Huelva. His son, Federico Clauss, always says that the germans took this corpse (WM), in an u-boat, in order to make an autopsy with their own doctors. Federico has been saying that for many years ago.
3. The corpse arrived to the beach of Huelva, on 30th April in 1943. And the first in may, it was left in the cemetery of Huelva. We have found an u-boat near the coast of Huelva (U-616), the same day. The U-616 received a encrypted message (may/1, 16:52h), that said to change the course.
If you are interested on this topic, write me your e_mail in order to give you more information about it.
Best regards
Enrique Nielsen