NEW YORK (CBSNewYork/AP) – After a long battle, Mayor Bill de Blasio fired the city’s Department of Investigation commissioner.

CBS2’s Dick Brennan explains the firing raises questions about the independence of the office.

Mark Peters has long been a thorn in the side of de Blasio.

There were embarrassing moments as Peters exposed corruption and city screw ups, everything from the correction commissioner taking his city owned car on vacation jaunts to NYCHA covering up lead paint inspections.

Citing an independent report that accused Peters of “deliberately misleading statements” and abusive behavior, De Blasio nominated Margaret Garnett as the next commissioner of the DOI. The commissioner is appointed by the mayor but operates independently.

Peters responded in a statement:

“Earlier today I was informed that the Mayor has fired me as DOI Commissioner. Per the City Charter, I have until next Wednesday to respond and I will do so in writing.”

The question is why was Peters fired?

“According to independent review by an investigator chosen by the outgoing commissioner, the very top leadership at DOI repeatedly undermined the values critical to its mission,” de Blasio said.

The mayor is referring to a report by James McGovern, focusing on a power grab made by Peters, trying to take control of the Special Commissioner of Investigation. Last month’s report by McGovern says Peters made misleading statements to the City Council and engaged in “intimidating and abusive behavior.”

“There had been abuse of power. There had been inappropriate treatment of employees. It’s quite clear from the McGovern report that these are not the type of activities becoming of a commissioner of DOI,” de Blasio said.

The firing of a commissioner who is usually known for the independence triggered a political firestorm.

“I strongly disagree with the Mayor’s firing of Commissioner Mark Peters–an act unprecedented in the 145-year history of DOI,” City Councilman Ritchie Torres said in a statement. “Were it not for the independence of Commissioner Peters, neither the public nor the City Council would have ever known about the suspicious sale of Rivington or the chronic failure of lead compliance in public housing, not to mention countless systemic failures elsewhere in city government.”

Public Advocate and Attorney General-elect Letitia James called it “reminiscent of Trump-like behavior.

De Blasio was asked if the firing would be akin to President Donald Trump firing Robert Mueller.

“It’s a ridiculous comparison. It’s apples and oranges if there ever was,” de Blasio said.

Peters’ firing comes after months of conflict with de Blasio.

Back in March, Peters led his department to take over the office that polices corruption in the school system despite objections from its members and the Department of Education. An inquiry board concluded two officials were fired or demoted because of their objections to the Department of Investigation seizing control of the office that fights corruption in New York schools.

Prior to her time with the New York State Attorney General, Garnett spent 12 years as a federal prosecutor in the office of the United States Attorney for the Southern District of New York, where she was responsible for prosecuting gang violence, racketeering, organized crime, violent crime, international terror and tax fraud.

Garnett will start next week.

James says she wants Peters to testify in front of the City Council about his pending cases.

City Comptroller Scott Stringer says he has been investigating Peters’ office for alleged lavish spending on office space.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)