Updated

A leading German researcher says he's uncovered documents unraveling one of the great mysteries of the end of World War II — what happened to Gestapo secret police head Heinrich Mueller?

For decades there were alleged sightings of Mueller in Cuba, Argentina and elsewhere. But Johannes Tuchel, director of Berlin's German Resistance Memorial Center, said Thursday he's uncovered evidence Mueller didn't make it out of Berlin.

He says several documents, including a 1945 death certificate and a grave digger's testimony to police in 1963, make it "clear-cut" to him that Mueller died and was buried near the Luftwaffe headquarters in the final days of the war.

He says Mueller was later disinterred and buried with thousands of others in a common grave in a Jewish cemetery destroyed by the Nazis.