Liberal billionaire George Soros has avoided paying billions in federal taxes by transferring assets to Ireland, a corporate tax haven, Bloomberg reported on Thursday.

Soros "had amassed $13.3 billion" by deferring taxes on fees paid by his hedge fund’s clients, according to Bloomberg. Efforts by U.S. lawmakers to close what some described as a loophole would have generated an additional $6.7 billion in tax revenue from Soros’ trading operation.

Just before Congress closed the loophole, Soros transferred assets to Ireland—a country seen by some at the time as a possible refuge from the law. The filings show for the first time the extent to which Soros’s almost $30 billion fortune—he ranks 23rd on the Bloomberg Billionaires Index—came from finding ways to delay taxes and reinvesting the money in his fund. […]

Soros might soften the potential tax blow by donating the money to the foundations, which often invest his contributions back into Quantum Endowment, according to their tax filings. That would only partially reduce the bill. Deductions for contributions to private foundations are limited to 30 percent of the donor’s adjusted gross income for the year, according to Jodi Krieger, an attorney with Kleinberg, Kaplan, Wolff & Cohen.

Soros may have found another way to defer paying taxes on fees. After Congress placed restrictions on U.S. investors in offshore funds in 1986, Soros created a security that enabled partners in his firm to defer taxes and convert ordinary income into lower-taxed capital gains, according to the person familiar with the firm’s finances. In 2010, Soros revived that maneuver by having Quantum Endowment issue $3 billion of convertible preferred partnership interests to "related parties" of Soros Fund Management, according to the Irish financial filings.