J.B. Pritzker has offered a simple response when Democratic and Republican rivals attack his family’s use of offshore banking to avoid taxes on its immense fortune: The trusts were set up in the 1960s by his grandfather, and the money goes to his charitable foundation.

“Any trusts for my benefit that are offshore, I have received no distributions from, and those trusts are only providing charitable contributions,” the billionaire Hyatt Hotels heir told reporters in December. “That’s all that they do.”

Those family trusts don’t tell the full story of Pritzker’s interests in the shadowy world of offshore finance, however.

A Chicago Tribune investigation found several offshore shell companies created between 2008 and 2011 — long after Abram “A. N.” Pritzker’s 1986 death — that are either wholly owned by J.B. Pritzker, his brother and business partner Anthony Pritzker, or list other close associates as controlling executives.

Many of the records about the governor candidate’s offshore interests were obtained by the Tribune through a reporting partnership with the International Consortium of Investigative Journalists, which maintains a database of millions of leaked offshore financial records collectively known as the Paradise Papers.

In the offshore world, wealthy people and corporations use the banking systems of low-tax countries, often island nations in the Caribbean, to shield their assets from taxing authorities in their home countries. Taxpayers in the U.S. are still responsible for paying taxes on any income they bring into the country from offshore assets. The secrecy of the offshore financial system, however, can make it difficult for the Internal Revenue Service to track what wealth U.S. taxpayers may hold outside the country, experts say.

The combination of Pritzker’s sprawling wealth, his decision not to release anything but the first two pages of his personal income tax returns, and the veiled existence of offshore companies tied to his businesses makes it difficult to determine the full scope of his assets or whether the Democratic governor candidate’s own financial interests may intersect — or conflict — with the business of the state of Illinois.

One of Pritzker’s offshore companies, Moreau Capital Holdings Ltd., is part of a venture that plans to buy city-owned land along the Chicago River to launch duck boat tours downtown. Pritzker is the sole owner of Moreau Capital Holdings, which was created in Nassau, Bahamas, in January 2011, according to records.

In recent weeks, the Tribune repeatedly asked the Pritzker campaign to make the candidate available to answer questions about his finances. After his staff did not respond to those requests, the Tribune last week sought out Pritzker at a campaign event at the University of Illinois at Urbana-Champaign. He quickly summoned a campaign press aide to run interference and declined to discuss his offshore dealings.

“You’re going to have to talk to my campaign about it,” said Pritzker, who started to walk away. “I know you guys are writing something and you’ve been talking to the campaign, and I really don’t have the details with me.”

The Tribune then submitted a list of questions about Pritzker’s financial ties to a series of offshore companies. His campaign declined to answer nearly all of those questions, except for one. Asked about M Cay Bahamas Ltd., Pritzker campaign spokeswoman Galia Slayen said it was created to hold the family’s real estate in the Bahamas in compliance with that country’s law.

Jack Blum, a Washington, D.C., lawyer who is an expert in money laundering and offshore tax issues, said it’s impossible to paint a complete picture of the tax structures and investment strategies Pritzker may enjoy while he campaigns in support of a graduated income tax increase to help fix Illinois’ finances. In general though, wealthy people use complicated offshore financial structures to avoid paying taxes on assets, he said.

“Illinois is bankrupt-plus. You have a hell of a problem. And the question you have to put is: You may want to come in with a platform of raising taxes, but why don’t you begin with telling us how you’ve escaped taxation by being offshore?” Blum said. “How are you separating yourself from the common man here?”

Pritzker a ‘PEP’

The bulk of the leaked Paradise Papers, which were obtained by the German newspaper Suddeutsche Zeitung, come from Appleby, a century-old offshore law firm that provides legal services to large corporations and wealthy individuals.

The New York Times reported that Appleby helps its clients reduce their taxes, set up offshore trusts that in some cases hold billions of dollars, and obscure their ownership of assets, such as companies.

The Times said Appleby designates some of its clients as “PEPs” — politically exposed persons — for whom “avoiding unwanted attention is a crucial goal.”

In Paradise Papers records reviewed by the Tribune, the Appleby firm labeled J.B. Pritzker as “PEP N-R,” a designation meaning he’s directly related to someone in a national government. The law firm declined to discuss its relationship with Pritzker or explain why it had applied the label to him. At the time, Pritzker’s sister, Penny Pritzker, served as commerce secretary for President Barack Obama. She has had her own offshore dealings revealed by the Paradise Papers.

J.B. Pritzker’s campaign confirmed the accuracy of reports in Forbes and Bloomberg News setting the candidate’s personal wealth at $3.5 billion. So far, he has pumped more than $63 million of his own money into his campaign in hopes of winning Tuesday’s Democratic governor primary against five others.

Andrew Stoltmann, a Chicago securities lawyer, said the sparse financial information that wealthy candidates like Pritzker release and the use of offshore trusts and holding companies allows them to keep their wealth from scrutiny.

“It’s byzantine. It’s complicated. And that’s just the way they like it,” Stoltmann said. “That’s why Pritzker running for governor is so fascinating. We should know more about his finances. But my guess is that (Republican Bruce) Rauner’s probably not any more forthcoming.”