From 1969 on, Marwan worked at the Presidential Office, first under Gamal Abdel Nasser and then as a close aide to his successor, Anwar Sadat.

[1] In 1968, Marwan started working in the Presidential Office under Sami Sharaf, Nasser's aide-de-camp and the strongman of the Egyptian security service, who kept an eye on him.

A few months later, Nasser, who was irritated by information concerning their lavish lifestyle, ordered the young couple to return to Egypt, where Marwan continued working under Sami Sharaf.

Although he held only a junior position under Nasser, the president occasionally used him for sensitive missions, such as calming the crisis that erupted after the resignation of General Saad el-Shazly from the army in response to his rival's nomination as chief of staff.

[8] Marwan continued to provide information to Israeli intelligence in London after Nasser's death and the rise of Anwar Sadat.

[6] Marwan's unparalleled access to his nation's best-kept secrets, especially after his promotion in May 1971, allowed him to provide Israel with information about the coming Yom Kippur War (1973), including detailed accounts of Egyptian war plans and military exercises, original documentation of Egypt's arms deals with the Soviet Union and other countries, the Egyptian military Order of Battle, the minutes from meetings of the high command, accounts of Sadat's private conversations with other Arab leaders, and even the minutes of secret summit meetings in Moscow between Sadat and Soviet leader Leonid Brezhnev.

[7] Some, most notably Eli Zeira in his memoirs and researcher Ahron Bregman, had previously posited that Marwan was a double agent who fed the Israelis misleading information as part of an Egyptian deception campaign.

[11] On February 14, 1974, Marwan became Secretary to the President of the Republic for Foreign Relations, a new position that reflected Sadat's ruling style.

When the accusations gained momentum, Sadat had to yield to the pressure and, in March 1976, ended Marwan's service in the Presidential Office.

[16][17] Marwan was nominated to head the Arab Organization for Industrialization, an arms production complex in Cairo that was financed by Saudi Arabia, the UAE, and Qatar.

Press reports indicted that the Metropolitan Police Service, as well as Marwan's elder son, Gamal, believed he had been murdered.

[24] Before his death, Marwan had reportedly been stressed and told his wife that he "might be killed"; he also began to check the door and locks before retiring each night.

[24] The evening on the day of his death, Marwan had been scheduled to take a flight to the United States for a meeting with his lawyer, and he had recently been admitted to the Reform Club.

Even if Israel believed that Marwan was a double agent, working for the Egyptians, better to do nothing and, through their silence, imply he was faithful to their cause.