Police suspect that a German man killed and dismembered his wife, cast her head in concrete and sank the body parts in an Alpine lake before drowning himself.
Investigators in Germany and Austria said Wednesday that the 72-year-old man likely killed his wife at their home near Frankfurt.
He then drove some 600 kilometres to sink her dismembered body in the Traunsee Lake in the Austrian Alps, they said.
Investigators are currently working on the assumption that it was a case of murder and suicide. But the man's motive remains unclear.
The gruesome crime came to light when two suitcases with remains of the 71-year-old woman surfaced in the Traunsee Lake at the weekend.
On Monday, police divers found the man's body, which was weighed down with heavy luggage tied to his hands.
Nearby in the water, they detected a concrete block containing the woman's head.
There was no sign that any third party was involved in the man's death, Austrian police said.
"The traces that officers found in the couple's apartment suggest that the women died there," German prosecutors and police in the Hessian city of Darmstadt said in a joint statement.
The man had apparently arrived in the Austrian town of Gmunden on December 30 and stayed in a hotel for several days before he sank his wife in the lake and drowned himself, Austrian investigators said.