German prosecutors on Tuesday dropped a case against a former SS soldier over his involvement in a 1944 massacre in France, because he was already convicted for the war crime by a French tribunal decades ago.
"Nobody can be punished for the same crime twice," the prosecutor's office in the northern city of Celle said in a statement.
The accused, 95-year-old Karl Muenter, was sentenced to death in absentia by a French military tribunal in 1949 for his role in the killing of 86 people in the northern French village of Ascq.
He was pardoned in 1955 as part of French-German reconciliation efforts after World War II.
German prosecutors said they agreed with an earlier assessment by French judicial authorities that the accused could not be prosecuted again for the same facts, a legal principle known as double jeopardy.
"The prosecutor's office in Celle has therefore closed its investigation due to procedural obstacles," the statement added.
Muenter was 21 years old and a member of the "Hitler Youth" SS division on the night of April 1, 1944, when a train carrying some 50 soldiers of the division was slightly derailed by an explosion in an act of sabotage by the Resistance.
The troops took revenge by shooting dead 86 men in the nearby village of Ascq, the youngest of whom was 15 years old.
Alexandre Delezenne, the great-grandson of one of the victims, strongly condemned the German decision to abandon the proceedings.
"I am very bitter that a Nazi can escape German justice, which was already under way to prosecuting him, because of a French legal opinion," he told AFP.
The dropping of the case marks the latest setback for German prosecutors racing against the clock to bring the last surviving former Nazis to justice for crimes committed during WWII.
Earlier this month, 96-year-old Oskar Groening, dubbed "the Bookkeeper of Auschwitz", died without ever serving his four-year sentence for being an accessory to the murders of 300,000 Jews at the infamous death camp.