One of Hillary Clinton’s key supporters – an Israeli billionaire who has donated more than $15 million to her presidential campaign and troubled family foundation – used a controversial Panamanian law firm to set up offshore companies and once admitted to a Senate panel that he used phony investment losses to dodge hundreds of millions of dollars in taxes.

Television and entertainment magnate Haim Saban, an Egyptian-born Israeli who made a fortune off of the “Power Rangers" children’s TV franchise and holds a lucrative stake in Univision, is among thousands of international movers and shakers whose names have surfaced in the Panama Papers. The vast trove of documents, leaked to a journalism consortium, show how celebrities, politicians and the rich use offshore companies to avoid taxes.

Saban and his American-born wife, Cheryl, are well-entrenched in the Clintons’ inner circle. They have donated $3.5 million to Hillary Clinton’s current campaign for president and more than $12 million to the Clinton Foundation, on which Cheryl Saban serves as a board member.

“For nearly two decades, Haim Saban has been a good friend, a loyal supporter, and trusted advisor to Hillary and me,” Bill Clinton told The New Yorker in 2010.

It is an odd relationship.

Hillary Clinton is promising voters that she will “close corporate tax loopholes and make the most fortunate pay their fair share.” Those pledges fly in the face of Saban’s tax avoidance practices.

Based in Los Angeles, the Saban Capital Group controls a dozen multimedia companies around the globe. Saban’s estimated net worth is $3.6 billion.

As a dual citizen of the United States and Israel, Saban wields legendary influence in both countries. But his propensity to create offshore entities raises an important question: Is he hiding taxable income from authorities in both countries?

Saban, 72, declined to comment for this story.

Saban’s flagship business is incorporated in the corporation-friendly state of Delaware, but a web of offshoots were established in offshore tax havens with the help of Mossack Fonseca, the Panamanian firm whose leaked documents provide a roadmap for international tax dodging. Among them are Saban S.A., which was set up in the British Virgin Islands in 1998, and Saban Ventures Corp., registered in the Seychelles in 2008.

U.S. Securities and Exchange Commission filings examined by Fox News identify a key Saban partnership called Ap. Sb. Ar. Cayman L.P., registered in the Cayman Islands by co-investors Apax Partners, Saban Capital, and Arkin Communications. In 2005, that partnership privatized Israel’s government-run telecommunications system, Bezeq, in a billion-dollar buyout sanctioned by then-Prime Minister Ariel Sharon, who called Saban his “dear personal friend.”

Saban financed the deal with loans from the government-owned Bank Leumi. Under Saban’s management, Bezeq paid huge dividends to its new shareholders before Saban sold it in 2010 for a "pre-tax” profit of $1.2 billion.

Months after buying Bezeq, Saban was spotlighted as a tax dodger by the U.S. Senate Committee on Homeland Security’s investigative report called “Tax Haven Abuses: The Enablers, the Tools and Secrecy.”

The report detailed how in 2001, Saban sold his share of the Fox Family cable channel to Disney for a capital gain of $1.5 billion. He signed off on a deal to create $1.46 billion in phony investment losses in order to, as he told the Senate, “save money on taxes."

Criminal sanctions followed for Saban’s lawyer and his investment advisors, but Saban testified that he had not read the documents that he had signed. He reportedly paid $250 million in back taxes to the IRS to settle the issue. But he continued to play the offshore game.

In 2013, working through his web of Delaware corporations and limited partnerships, Saban took control of another Israeli telecommunication group, Partner Communications. Partner’s board of directors includes several former Bezeq directors, including Saban’s brother, Arieh Saban.

The Sabans donate to the Clinton Foundation and other entities through the Saban Family Foundation. It disburses regularly multimillion dollar grants to its favorites: the Clinton Foundation, the Brookings Institution, Friends of Israeli Defense Forces, and various lobbyists for Israeli interests in the United States.

But not all of the billionaire’s philanthropy supports his political and business agendas. In 2014, the foundation donated $11,000 to buy toys for “children across North America and around the world.” Saban also gave $5,000 to the Dream Center Foundation for “needs in the areas of homelessness, hunger, poverty, addiction, education, and human trafficking” and $1,500 to Girls Inc. to encourage “media literacy.”