Michael Atkinson, the inspector general removed by President Trump late Friday, said he believes he was fired for having properly handled a whistleblower complaint that became a centerpiece of the case for the president’s impeachment.

“I am disappointed and saddened that President Trump has decided to remove me as the inspector general of the intelligence community because I did not have his ‘fullest confidence,’ ” Atkinson said in a seven-paragraph statement issued Sunday. “It is hard not to think that the president’s loss of confidence in me derives from my having faithfully discharged my legal obligations as an independent and impartial inspector general.”

That Atkinson issued a statement at all is unusual — inspectors general usually stay silent when removed, but the circumstances leading to his firing are also highly unusual.

Inspectors general are traditionally removed for “cause” — usually involving misconduct. In Atkinson’s case, there was no apparent misconduct. Rather, Trump said in a letter to Congress on Friday night that it was “no longer the case” that Atkinson had his “fullest confidence.”

On Saturday, Trump elaborated on his decision to remove Atkinson. “I thought he did a terrible job. Absolutely terrible,” he said at a news briefing on the coronavirus pandemic. “That man is a disgrace to IGs.”

Trump’s move, however, drew rebukes from Democrats and former intelligence officials who have served in Republican administrations. Michael Horowitz, the chairman of the Council of the Inspectors General on Integrity and Efficiency and the Justice Department inspector general, said in a statement Saturday that Atkinson is known throughout the inspector general community for his “integrity, professionalism and commitment to the rule of law and independent oversight.”

That, Horowitz said, “includes his actions in handling the Ukraine whistleblower complaint, which the then-Acting Director of National Intelligence stated in congressional testimony was done ‘by the book’ and consistent with the law.”

Sen. Charles E. Grassley (R-Iowa), chairman of the Senate Whistleblower Protection Caucus, demanded more information on Atkinson’s removal. Inspectors general “often serve as an outlet to whistleblowers” who “shine a light” on problems in government, he said. “They help drain the swamp, so any removal demands an explanation.”

Atkinson, who took office in May 2018, received a complaint in August from an intelligence community official who raised concerns about Trump pressuring the Ukrainian president to undertake investigations of a likely political rival in the 2020 presidential campaign. He found the complaint both “urgent” and credible, and following the whistleblower law, he sought to have it transmitted to Congress within seven days.

The administration at first tried to block it but relented following, among other things, media revelations about the complaint’s substance. The subsequent firestorm led to Trump’s impeachment by the House in December. He was acquitted by the Senate in February largely along party lines.

But the impeachment — what the president has repeatedly condemned as “a hoax” — consumed Trump, and he made it clear to aides that he was not happy with Atkinson. On Friday, Trump gave notice of his intent to fire Atkinson, the latest in a long line of officials removed by the president after he deemed them disloyal.

Although some, like Atkinson, may be presidential appointees, inspectors general are supposed to operate with a degree of independence to investigate fraud and misconduct without fear of retaliation. And they often are retained from one administration to the next, even across party lines.

“Although I have proudly served as a political appointee since May 2018,” Atkinson said, “I have never been a political or partisan person.” Atkinson has served 17 years in government, most of those in the Justice Department.

Atkinson also said he was legally bound to ensure that officers who “blow the whistle in an authorized manner” have their identities protected as a guard against reprisals. Trump and his allies repeatedly sought to publicly out the whistleblower, who is still employed in the intelligence community. His lawyers received threats against themselves and the whistleblower.

“Atkinson’s statement says what anyone who follows the rule of law knows: He was fired for fulfilling his legal responsibilities to protect a whistleblower who lawfully reported concerns regarding President Trump,” said Mark Zaid, who formerly represented the whistleblower. “Protecting whistleblowers is not a partisan activity, and those who say otherwise threaten the integrity of our governmental system and undermine our democracy.”