Hunter Biden, son of President Joe Biden, sued the U.S. Internal Revenue Service Monday. He claimed that whistleblowers working for the U.S. Tax Agency had illegally disclosed his taxes.

The lawsuit was filed at the U.S. District Court for the District of Columbia and focused on statements made in media interviews by IRS agents Gary Shapley, Joseph Ziegler, and others. This came amid a lengthy investigation by House of Representatives Republicans of the younger Biden’s taxes and dealings.

Hunter Biden, age 53, finds himself in the middle of a political storm as House Republicans launch an impeachment investigation against his father. The inquiry is centered on alleged links between his business and his father’s policies from 2009-2017, when his father was vice president. The Republicans have not presented any evidence that shows the elder Biden benefited from his son’s businesses. The White House denies any wrongdoing.

Hunter Biden, the son of an American president in office, is the first to be criminally charged. Last week, prosecutors charged him with three counts relating to his lying about having used illegal drugs at the time he purchased a gun. Hunter Biden had previously reached a deal with prosecutors over gun and tax charges. However, the plea agreement collapsed.

The lawsuit filed on Monday refers to the “more than twenty nationally televised interviews and public statements made by Shapley and Ziegler, and not sanctioned by Congress” about Hunter Biden. Shapley, Ziegler and their lawyers have testified before Congress about the alleged political interference with an IRS investigation of Biden’s tax returns. The Justice Department denies any such interference.

The lawsuit states: “The lawsuit concerns the IRS employees and their representatives’ decision to ignore their obligations, repeatedly and deliberately disclose and disseminate protected information from Mr. Biden’s tax returns outside of the exceptions allowed by law for disclosures.”

Biden wants $1,000 for every unauthorized disclosure of tax return information. He also wants a declaration by the IRS, an IRS data security plan, documents related to Biden’s taxes, and other relief.

Shapley’s team of lawyers said that the suit was a frivolous attempt by Biden family attorneys to divert attention from Hunter Biden’s own legal issues and intimidate current and future whistleblowers.

In a press release, Ziegler’s lawyer said that the Biden family lawyers would not be successful in their efforts to silence Ziegler.

The IRS didn’t immediately respond to an inquiry for comment.

In a social media post, the Republican-led House Judiciary Committee referred to the lawsuit as “intimidation”.

Hunter Biden also filed a suit last week against a former White House assistant during Donald Trump’s presidential term over the aide’s alleged involvement in the publication embarrassing images and email.

Trump was the first U.S. President to be impeached two times. Both times, the Senate cleared him. Trump has also been charged with four criminal cases in this year.