"Because of my expertise in the construction of execution equipment, I was asked to testify by the defense team of Mr. Ernst Zundel, a German national living in Canada, for some 20 odd years, who published a pamphlet, 'Did Six Million Really Die?'."
January 1, 1970
https://en.wikiquote.org/wiki/Mr._Death%3A_The_Rise_and_Fall_of_Fred_A._Leuchter%2C_Jr.