It was because of the ease of how Jews travelled throughout the Ottoman Empire was Passi and many other Jewish double agents able to remain uncaught for a long time, sometimes never.
During these times, he was informing Sultan Murad III of any noteworthy developments and intelligence he could gather in Europe, and was working with Elizabeth I on the issue of the War of Polish Succession.
Grand Vizier Koca Sinan Pasha did not trust Passi, especially because of his close ties to Spain and his involvement in the Polish succession question.
[9][10] [11] High-ranking officials such as Chief of Janissaries Mehmed Ağa, Occhiali, and Cığalazade Yusuf Sinan Pasha, (the latter two who were both Italians in the service of the Sublime Porte), supported Passi against the Grand Vizier as they were either pro-Spain or anti-Venice.
Soon after this, William Cecil, Elizabeth's Lord High Treasurer, wrote to Mendes to assure him of English backing should the Sultan ever be subjected to such a case.
The Venetian ambassador to the Ottoman Empire found that a Spanish agent, Giovanni Steffano Ferrari, was providing a salary to Passi for his services.
[19] [13] The English had promised the Ottomans Villefranche, Toulon, or Marseille if they could successfully depose Philip II and place António on the throne.
[11] Passi was aware of this as he was in the daily meetings where Koca Sinan Pasha, among other High-ranking individuals, discussed and oversaw the naval preparation, which was called in January 1590.
[23] After Koca Sinan Pasha himself was dismissed on August 2, 1591, Passi's son, Arslan, wrote a letter to Murad III for the release of his father who had been 'innocently exiled to Rhodes due to ill will'.
German–Indian scholar Suraiya Faroqhi claims that Passi was free between 1591 and 1592, but was imprisoned and most likely executed by Koca Sinan Pasha in 1593, after he had assumed power as Grand Vizier for the third time on January 28, 1593.