Iranian-born Daniel James, 45, who was the personal interpreter to General David Richards, told the Old Bailey that he used pictures, dust, candles and seashells to cast spells protect his boss.
He also said he did Tarot card readings for other personnel at the Allied HQ in Kabul to predict the future.
James is alleged to have passed on secret information about Allied troop movements to the Iranians - who then passed it on to the Taliban.
Giving evidence, James swore on the Bible but said he embraced all religions before telling the court how he converted to Voodoo while on his yearly trips to Cuba to research salsa in 2003.
He claimed to be a priest who had recorded 10 Voodoo DVDs.
