At least 10 FBI employees who worked on former Special Counsel Jack Smith’s investigation into President Trump’s retention of classified records after he left the White House in 2021 were fired on Wednesday, multiple sources told CBS News.

The firings came after Reuters reported that the FBI had subpoenaed records of phone calls made by FBI Director Kash Patel and White House Chief of Staff Susie Wiles when they were still both private citizens as part of Smith’s probe into Trump.

The Reuters article quoted Patel, who alleged that the FBI had secretly subpoenaed his phone records “using flimsy pretexts and burying the entire process in prohibited case files designed to evade all oversight.” The Reuters article added that it had not independently verified any of Patel’s claims.

Patel did not provide any evidence of wrongdoing by the staff who were terminated.

Special Counsel Jack Smith oversaw two federal probes into now-President Trump. One case alleged he unlawfully tried to overturn the results of the 2020 presidential election, while the other focused on his retention of classified documents and efforts to obstruct the Justice Department when it asked him to return the files.

All of the FBI agents and analysts who were fired on Wednesday were involved with the classified documents case.

CBS News confirmed with a source familiar with the matter that Wiles’ records were reviewed as part of the documents case, but was unable to verify whether Patel’s were. In the case involving the 2020 election, known as Arctic Frost, Patel’s records were not subpoenaed, the source added.

CBS News has reached out to the FBI for comment.

The FBI Agents Association, which represents current and former agents, condemned the firings in a statement, saying they violate FBI employees’ due process rights.

“These actions weaken the Bureau by stripping away critical expertise and destabilizing the workforce, undermining trust in leadership and jeopardizing the Bureau’s ability to meet its recruitment goals—ultimately putting the nation at greater risk,” the group said.

Smith’s dual investigations into Mr. Trump led to the first federal criminal indictments against a former president in U.S. history. The classified document charges were dismissed by a federal judge in Florida in mid-2024 on the grounds that Smith was unlawfully appointed, and Smith dropped the 2020 election charges after Mr. Trump won the 2024 race.

Since then, the Trump administration has taken aim at federal employees who worked on the two cases. The Justice Department fired a group of prosecutors who worked on Smith’s team, and the FBI has fired agents involved in the Arctic Frost election investigation.

The investigations into Mr. Trump drew another round of controversy late last year, after the GOP-led Senate Judiciary Committee revealed that the FBI obtained several Republican lawmakers’ phone records as part of the Arctic Frost probe. Those records included basic information about who the lawmakers called in the days surrounding the Capitol riot on Jan. 6, 2021, but didn’t include the contents of their phone calls.

Mr. Trump called for Smith, former Attorney General Merrick Garland, former FBI Director Christopher Wray and other officials to be “prosecuted for their illegal and highly unethical behavior” in October.

Attorneys for Smith called his actions “entirely lawful, proper and consistent with established Department of Justice policy.”