House Republicans have accused the Federal Bureau of Investigation (FBI) of intentionally retaliating against conservative agents and suspected whistleblowers by revoking security clearances.

Both House and Senate Republicans have raised concerns over increasingly politicized misconduct within the FBI. Recently, Washington, D.C. agent Timothy Thibault was investigating Hunter Biden until he suddenly resigned in August to avoid being subjected to an internal review.

Iowa Sen. Chuck Grassley (R) the ranking member of the Senate Judiciary Committee, has also claimed that whistleblowers have approached his office to report internal misconduct in the bureau’s investigations into former President Donald Trump, according to The Daily Caller.

Republican Reps. Jim Jordan (OH), Darrell Issa (CA), and Mike Johnson (LA) alleged in a letter to FBI Executive Assistant Director Jennifer Leigh Moore that the FBI is cracking down on suspected whistleblowers in response.

“Once a whistleblower makes a protected disclosure, an agency is prohibited from retaliating against the employee for that disclosure by taking or failing to take a personnel action,” the Republicans wrote. “Your efforts to interfere with FBI employees who seek to expose the Bureau’s misconduct by communicating directly with Congress cannot be condoned.”

FBI agent Steve Friend was reportedly suspended and escorted from a Florida field office after he declined to participate in an arrest operation targeting a Jan. 6 Capitol riot suspect. Friend filed a whistleblower report detailing his experience, according to the New York Post.

Other whistleblowers have reportedly alleged that the FBI is pulling agents off of child sexual abuse cases to investigate the Capitol riot and that bureau superiors told agents not to look into Hunter Biden’s laptop.

The FBI has denied the allegations.

“The FBI does not target or take adverse action against employees for exercising their First Amendment rights or for their political views; to allege otherwise is false and misleading.The FBI is required to follow established policies and procedures, to include a thorough investigation, when suspending or revoking a security clearance. The FBI takes very seriously its responsibility to FBI employees who may make protected disclosures under the whistleblower regulations.  FBI employees who report evidence of wrongdoing through a protected disclosure are protected from retaliation,” a spokesperson said.