US Democrats have launched another investigation into President Trump after the firing of the state department’s internal watchdog.

Inspector General Steve Linick was reportedly investigating Secretary of State Mike Pompeo for suspected abuse of office.

Trump sent a letter to House Speaker Nancy Pelosi on Friday decalring his intention to fire the State Department Inspector, claiming he “no longer” had confidence in him.

On Saturday, House Foreign Affairs Committee Chairman Eliot Engel (D-New York) and Senate Foreign Affairs Committee Ranking Member Bob Menendez (D-New Jersey) sent a letter to the White House, alleging the firing was “politically-motivated,” and announced an investigation.

The BBC reports: The former prosecutor was appointed by Mr Trump’s predecessor, Barack Obama, to oversee spending and detect mismanagement at the state department.

On Saturday, top Democrats on the House and Senate Foreign Relations Committees questioned the timing of Mr Linick’s removal and announced an immediate investigation.

“We unalterably oppose the politically-motivated firing of inspectors general and the president’s gutting of these critical positions,” Congressman Eliot Engel and Senator Bob Menendez said in a statement.

They said Mr Linick had “opened an investigation into wrongdoing by Secretary Pompeo himself”, adding that his firing was “transparently designed to protect Secretary Pompeo from personal accountability”.

Mr Linick had begun investigating allegations that Mr Pompeo had improperly used staff to run personal errands, US media report.

Mr Engel and Mr Menendez have requested that the White House and State Department hand over all records related to his dismissal by next Friday.

Meanwhile, on Saturday, the White House said the decision to oust Mr Linick was prompted by Mr Pompeo himself. “Secretary Pompeo recommended the move, and President Trump agreed,” an official said.