The comments came after top-selling Bild newspaper reported that the "likes" came from the verified Twitter account of German diplomat Christian Clages, @GerRepRamallah.
The multiple "likes" included one for a video praising an attack on Israeli soldiers, and another for an exchange between American white supremacist David Duke and another user about an alleged massacre of Jews.
"The Foreign Ministry disassociates itself emphatically from the tweets mentioned," the ministry said in a written statement to The Associated Press. "The content is unacceptable and contradicts the views of the German government."
It said it has initiated an in-house investigation to determine "how these 'likes' came about and will then determine consequences."
The ministry said "Clages has explicitly distanced himself from the statements in the tweets."
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