Spokesmen for the IRS and the U.S. attorney’s office in Manhattan, which is representing the tax agency, declined to comment.

Complex Policy

Rosner, who runs his own firm called called Graham Fisher & Co., is one of a number of experts who hedge funds hire confidentially to navigate complex policy matters. Demand for such work increased during the crisis with the government’s unprecedented intervention in the financial system.

Rosner’s adjusted gross income was $673,636 in 2008, up from $174,554 in 2006, court documents show. He’s been most sought out for his views on Fannie and Freddie, the housing-finance companies that helped fuel the economic downturn.

One of Rosner’s specialties, according to people who have worked with him, is advocating on Twitter and in media interviews for policies that would benefit clients. Bloomberg is among the news organizations he has spoken with. Paulson and Elliott have both retained Rosner’s services in the past, said the people who asked not to be named because the arrangements are confidential.

“To imply that my opinions, which are often contrary to the financial interests of some of my clients, are anything other than my own is false,” Rosner said in his statement to Bloomberg. “My work is the result of intense research, and investors and policy-makers seek out my opinions because over time they have been proven accurate.”

A spokeswoman for Paulson declined to comment, while a spokesman for Elliott didn’t respond to calls and emails.

Anonymous Lawsuit

Rosner first filed his tax case in 2016 under the name John Doe, though his name was added to the docket a year ago after the judge ruled that he couldn’t remain anonymous.

For now, Rosner has been allowed to keep his clients’ names under seal. He’s argued that the firms are “central figures” in the economy who retained him under strict confidentiality. One required notification if there was a chance it could be mentioned in a court proceeding.