Nazi Hunter Sues Wiesenthal Center -- You're PROTECTING a War Criminal

Some of the most powerful Jews in the U.S have concocted a massive conspiracy to discredit a Nazi hunter who claims he uncovered some explosive new information about the Holocaust ... this according to a lawsuit obtained by TMZ.

The Nazi hunter behind the suit is Mark Gould (pictured above) -- who claims he recently managed to track down a 98-year-old former SS lieutenant colonel named Bernhard Frank (pictured below) ... and got him to admit he had a MAJOR role in the Germany's decision to exterminate the Jews.

Gould claims he thought his findings would impress the honchos at the famous Wiesenthal Center in L.A. -- a powerful Jewish organization dedicated to documenting the Holocaust -- since he had been working with them since 2004. But Gould was wrong.

Instead, Gould claims the leaders of the Wiesenthal Center ran a smear campaign against him in 2010 -- hoping to discredit Gould's findings so Frank would NOT be portrayed as a key Nazi figure.

As for why the Weisenthal Center is trying to discredit Gould ... one Center official published an article saying Frank was like a secretary who prepared documents but had no real decision-making power. The suggestion -- Nazi hunters should focus on the honchos, not the lackeys. And the Center believes Gould is after fame, not justice.

Gould claims in his lawsuit the Center never presented any proof that would discredit his work --but still ran a defamatory campaign against him, to destroy his credibility.

Now, Gould thinks the Center should pay for the "hypocrisy and betrayal" -- he's suing for unspecified damages.