The interim head of an independent civilian police oversight board in New York, who had criticized the Police Department and had sought more investigative power and funding for the agency, resigned on Monday after being forced out by Mayor Eric Adams.

The chairwoman, Arva Rice, was asked in April to resign from the panel, the Civilian Complaint Review Board, by Philip Banks III, the deputy mayor for public safety. The request came after she criticized police officials for delaying an investigation into the fatal shooting of a Bronx man by failing to turn over evidence in a timely manner.

Ms. Rice, who also serves as president and chief executive of the New York Urban League, has led the board since the mayor installed her in February 2022, when he called her a “champion for equity and justice.” Her resignation will take effect on Aug. 15.

“While I will no longer serve on the C.C.R.B., my commitment to holding police officers accountable for misconduct remains unchanged,” Ms. Rice wrote in her resignation letter, which was reviewed by The New York Times.

Among her accomplishments are investigating the police response to the protests over the murder of George Floyd in 2020, during which 138 officers were found to have committed misconduct, and clearing a backlog of complaints made during the coronavirus pandemic. Ms. Rice requested $15 million more in funding from the City Council than the mayor proposed in his budget this year. She also pushed for a change in state law that would allow the board more access to police body camera footage.