Haj Amin el-Husseini was the Mufti of Jerusalem between 1921-1937 and was in exile and in collaberation with the Nazis during the years 1941-1945.
European Jews were the victims of Nazi anti-Semitism. However, this racist philosophy applied to all members of the "Semitic race" - including Arabs. The Nazi leadership expressed complete disdain towards the Arabs and were confused by the efforts of el-Husseini, to curry favor with Germany prior to the outbreak of World War II.
According to Arie Stav's article Arabs and Nazism, in OUTPOST, January 1996:
The Mufti was never tried because the Allies were afraid of the storm in the Arab world if its national hero were to be treated as a criminal. The Mufti was received as a national hero in Egypt where he was among the sponsors of the 1948 war. Indeed, the Mufti represents the link connecting the two attempts to destroy the Jews, that of the Nazis and that of the Arabs. It is thus not surprising that the Mufti has a lofty place in the PLO's pantheon. Arafat saw the Mufti as an educator and leader, declaring in 1985 that he deemed it an honor to walk in his footsteps. Arafat stressed that the PLO continued to march in the path carved out by the Mufti."
Additional References