Israeli billionaire Idan Ofer and his wife Batia are quitting a Harvard executive board in protest of how university leaders have responded to Hamas' terror attacks on Israel.

"Unfortunately, our faith in the University's leadership has been broken and we cannot in good faith continue to support Harvard and its committees," the couple said in a statement to CNN.

Idan Ofer has amassed a fortune valued at nearly $20 billion, according to Bloomberg's billionaire index, where the Israeli ranks No. 80.

The decision by the Ofers to step down from the executive board of Harvard's Kennedy School of Government adds to the swirl of controversy at the university following the release of an anti-Israel statement by a coalition of student groups.

That letter solely blamed Israel for the deadly attacks by Hamas, setting off a firestorm and prompting some students to distance themselves from it.

The anti-Israel letter was not the main reason the Ofers decided to resign and criticize Harvard leadership, a person familiar with the matter told CNN on Friday. Instead, the resignation was driven by how Harvard leaders responded to the attacks on Israel, the source said.

"We denounce those who seek to place blame on the people of Israel for the atrocities committed by the terrorist organisation, Hamas," the Ofers said.

"Our decision" to resign from the board "has been precipitated by the lack of clear evidence of support from the University's leadership for the people of Israel following the tragic events of the past week, coupled with their apparent unwillingness to recognize Hamas for what it is, a terrorist organization," the Ofers said.

The Kennedy School board is chaired by billionaire David Rubenstein and includes business and philanthropic leaders who advise the dean and are "among the most committed financial supporters" of the school, according to its website.

Idan Ofer is a son of shipping billionaire Sammy Ofer, who was once Israel's richest man and died in 2011, according to Forbes. He owns a majority stake in Israel Corp., an energy, shipping and chemicals conglomerate. He is also a controller shareholder in Kenon Holdings, a New York-listed holding company.

With so much disinformation being spread by social media it is essential that the world's great institutions speak with a clear and unequivocal voice at this critical time.

Harvard did not comment on the resignation and criticism from the Ofers. The university instead pointed to a video statement released Thursday night by Harvard President Claudine Gay.

"People have asked me where we stand. So, let me be clear. Our University rejects terrorism -- that includes the barbaric atrocities perpetrated by Hamas," Gay said. "Our University rejects hate -- hate of Jews, hate of Muslims, hate of any group of people based on their faith, their national origin, or any aspect of their identify."

Gay added that Harvard "rejects the harassment or intimidation of individuals based on their beliefs" and "embraces a commitment to free expression."

"That commitment extends even to views that many of us find objectionable, even outrageous. We do not punish or sanction people for expressing such views," Gay said. "But that is a far cry from endorsing them."

After the anti-Israel statement was released, CEOs and business leaders including hedge fund billionaire Bill Ackman called for the public release of the names of students linked to the organizations that backed the statement. That's despite the fact that some student distances themselves from the letter or said they hadn't seen it.

A billboard "doxing truck" drove near Harvard's campus on Wednesday displaying the names and faces of students that apparently were linked to the statement.