The mystery surrounding Heinrich Mueller -- the highest-ranking Nazi never to have been captured or confirmed dead after World War II -- might have just been solved. According to the Associated Press, a German researcher has come forward to claim that the head of the Gestapo secret police died in 1945 near Luftwaffe headquarters in Berlin.

Johannes Tuchel, director of the German Resistance Memorial Center in Berlin, said he found a death certificate verifying his claim. He also said he has other evidence that shows Mueller’s body was discovered by a work crew cleaning up corpses a few months after the end of the war. According to the AP, Mueller’s body was then buried in August 1945 along with 3,000 others in a mass grave on the site of what used to be a Jewish cemetery, of all things.

“Mueller didn’t survive the end of the war,” Tuchel told German newspaper Bild, according to the New York Post. “His body was interred in 1945 in the Jewish cemetery in Berlin-Mitte in a mass grave.”

The news angered Dieter Graumann, a leader of the Jewish German community, according to the Post.

“That one of the most brutal Nazi sadists is buried in a Jewish cemetery is a distasteful monstrosity,” he told Bild. “The memory of the victims is being treated here with contempt.”

But not everyone is convinced that Heinrich Mueller is buried in Berlin. Efraim Zuroff, the top Nazi-hunter for the Simon Wiesenthal Center, told the AP he needs to see DNA evidence.

“The Nazis who wanted to escape very often took measures to create false documents faking their death,” he told the AP from London. “I would be very wary of reports like that without forensic evidence.”

In addition to the death certificate, Tuchel told the AP he has evidence that Mueller’s identity papers and medals were given to military authorities to hand over to his family. Tuchel also said he discovered testimony from a gravedigger in 1963, who told police he buried Mueller in the former Jewish cemetery after he matched the identity papers to the face of the body.

As the AP notes, Mueller – who held the rank of SS Gruppenfuehrer and was present at the 1942 Wannsee Conference where the "Final Solution" for the extermination of the Jewish people was hatched  -- has been wanted for decades by organizations all over the world, including Mossad in Israel, the U.S. Office of Special Investigations and the Simon Wiesenthal Center.

After the war, there were alleged sightings of Mueller in countries like Argentina, Cuba and Czechoslovakia, the AP said. However, it has generally been believed -- but never confirmed -- that the top Nazi died in Berlin in 1945.