Billionaire Leon Black declined to appear under subpoena Thursday to answer questions from the House Oversight and Government Reform Committee about his relationship with Jeffrey Epstein and instead sued the panel, arguing the subpoenas are invalid.

Black, 75, co-founder of Apollo Global Management, had previously given a voluntary interview to the committee earlier this year. Lawmakers later issued subpoenas seeking additional testimony and nondisclosure agreements after saying he refused to answer certain questions. The subpoenas required him to produce documents and testify on September 3.

In a lawsuit filed in federal court in the District of Columbia, Black’s attorneys contend the subpoenas exceed the committee’s authority by seeking private information with no legitimate connection to its legislative purpose. They also argue the demands could expose private details of women who have no known public connection to Epstein.

“This is no longer about finding the truth about Epstein. It is about trying to destroy Mr. Black,” attorney Susan Estrich said in a statement. “We were left with no choice but to file this lawsuit in response to an abuse of Congressional power.”

Committee Chairman James Comer (R-Ky.) called Black’s decision “a shame,” noting that the investigation is examining how the government failed for years to properly investigate and prosecute crimes committed by Epstein and Ghislaine Maxwell, and how Epstein cultivated influential people to avoid scrutiny. “Mr. Black’s testimony is crucial to our investigation as he was one of Mr. Epstein’s fee-paying clients and has several nondisclosure agreements,” Comer said.

Several Democrats on the panel, including Rep. Jasmine Crockett (D-Texas), called for a contempt vote, arguing that survivors deserve answers.