Omar Suleiman, 76, former Egyptian intelligence chief and Egyptian vice president, died on Thursday while undergoing a medical test in the US.

Suleiman was a trusted associate of ousted Egyptian president Hosni Mubarak who also maintained close relations with the Israeli security and political establishment.

Reportedly he was not in failing health, and Reuters quoted aide Hussein Kamal as saying, “He was fine. It came suddenly while he was having medical tests in Cleveland.”

Omar Suleiman was born in 1936 in Qena in southern Egypt, joined the army in 1954 and started his career in intelligence in 1986, eventually becoming director of the General Intelligence Service in 1993, a post he would hold for almost 20 years.

In his military career, he was among the soldiers sent by Egypt to Yemen during the 1962 civil war and fought against Israel during both the Six-Day War of 1967 and the Yom Kippur War of 1973.

As Egypt’s intelligence head he became one of the most powerful men in the country and Mubarak’s trusted deputy. For most of that time he played a behind-the-scenes role and was considered a ruthless opponent of Islamic militants operating in Egypt.

On Thursday, MK Binyamin Ben-Eliezer (Labor), who has close ties with Mubarak, called Suleiman “an Egyptian patriot who was one of the leading forces in blocking Hamas,” Ynet News reported.

Suleiman was appointed vice president on Jan. 29, 2011, at the peak of the Egyptian uprising, a desperate attempt by Mubarak to save his political life as hundreds of thousands of Egyptians took to the streets demanding his ouster.

After the revolution, Suleiman disappeared from public view only to come back as a presidential candidate, sparking fears of a Mubarak regime comeback. However, shortly after registering as a candidate, the country’s election commission in a surprising move disqualified him for not having received enough signatures on his candidacy papers.

In his most recent public comments, Suleiman said he decided to run for president to prevent Islamists from turning Egypt into a “religious state,” and warned that the country would be internationally isolated if one of them became president.

Mohammed Morsi, an Islamist from the Muslim Brotherhood group, won the presidency last month.