In 1580, alcalde mayor of Atucpa Diego Díaz del Castillo took Alexandre Testanegra, a Greek sailor and former Ottoman Janissary, to jail. Diaz del Castillo prosecuted Testanegra for the charges of spying and creating maps and charts of the Spanish dominions for his master Sultan Selim II. The alcalde gathered twenty-one testimonies that helped to put together a composite picture of Testanegra’s adventures in Venice, Naples, Spain, America, the Philippines, China, Jerusalem, and Istanbul. Because of the severity of the testimonies, the Royal Audiencia of Mexico, the highest court of justice in the New Spain, took the case. Testanegra posed a significant threat to the crown and to the authorities of New Spain. The Spanish monarchy feared the Ottomans not only in the Mediterranean but also in the Indian Ocean. Now, it appeared that the Ottomans were collecting intelligence to attack America. When the Audiencia was unable to convict the Testanegra on charges of espionage, it transferred the case to the Inquisition to investigate him for heresy. The main evidence that the Inquisition had to prosecute Testanegra was an apparent circumcision and his suspicious origins –Greece was an Ottoman domain–. After tough interrogations Testanegra confessed that he was a vassal of the Sultan and that he had a Muslim background. Despite his revealing declarations, he successfully eluded conviction. Was Testanegra really a spy? Why would the Ottomans have been interested in Spanish America? How did the Greek sailor overcome the most powerful tribunals of justice in New Spain? This essay argues that Testanegra was indeed a spy and that he was effectively collecting intelligence about America. This essay also analyzes how this mam with Muslim and Ottoman ties settled in New Spain and successfully eluded conviction from the charges issued by the most powerful institutions in New Spain.