Trump, in a letter to House Speaker Nancy Pelosi late Friday, said he no longer had confidence in Inspector General Steve Linicks ability to serve. The letter did not specify a reason for the latest in a string of government watchdogs to be removed in recent weeks under the Republican president.

The Democratic-led House Foreign Relations Committee, along with colleagues in the Senate, in a statement questioned the timing and motivation of what they called an unprecedented removal.

We unalterably oppose the politically-motivated firing of inspectors general and the Presidents gutting of these critical positions, wrote House panel chairman Eliot Engel and Senator Bob Menendez, the ranking Democrat on the Republican-led Senate Foreign Relations panel.

Engel and Menendez called on the Trump administration to turn over any related documents by May 22.

The two Democrats said it was their understanding that U.S. Secretary of State Mike Pompeo personally recommended Linicks firing because the inspector general had opened an investigation into wrongdoing by Secretary Pompeo himself.

Representatives for the White House and the department could not be immediately reached for comment on the probe.

Linick, appointed to the role in 2013 under the Obama administration, is the fourth inspector general fired by Trump since early April following his February acquittal by the Republican-led Senate in his impeachment trial.

Pelosi described the ousting as an acceleration of a dangerous pattern of retaliation.

The U.S. Department of State later said Stephen Akard, the director of the Office of Foreign Missions, would replace Linick.

In April, Trump removed a top coronavirus watchdog, Glenn Fine, who was to oversee the governments COVID-19 financial relief response. He also notified Congress that he was firing the inspector general of the U.S. intelligence community, Michael Atkinson, who was involved in the triggering the impeachment investigation.

Earlier in May, Trump ousted Christi Grimm, who led the U.S. Department of Health and Human Services Office of the Inspector General (OIG) after accusing her of having produced a fake dossier on American hospitals suffering shortages on the frontlines of the novel coronavirus outbreak.

Trump is methodically eliminating anyone who would bring wrongdoing to light, Senator Jeff Merkley, a Democrat on the Foreign Relations panel, tweeted.