The troubled police force in Oakland, California, has lost its third police chief in eight days as it struggles with allegations of sexual misconduct and racist text messages.

Oakland Mayor Libby Schaaf told a news conference on Friday that acting police chief Paul Figueroa resigned his duties just two days after he was appointed to replace Ben Fairow as the department's police chief.

Schaaf had replaced former police chief Sean Whent with Fairow last week. Schaaf declined to elaborate on the move aside from saying Whent made a "personal choice."

Schaaf removed Fairow on Wednesday, saying only that she received "information" that made her question whether he could lead the department.

Schaaf also denounced the department's "toxic, macho culture" and vowed to eliminate "the bad apples."

"I want to assure the citizens of Oakland that we are hell-bent on rooting out this disgusting culture," she said angrily.

Schaaf declined to provide details about the ongoing investigation into allegations of sexual misconduct against the department, claiming that releasing information could impede the probe and possible charges.

As many as 21 officers from the Oakland police department and other area law enforcement agencies had sex with a teenage prostitute, the local East Bay Express newspaper reported last Friday.

Along with dozens of other police departments around the nation, the Oakland police have come under scrutiny during the past year.

A recent study by Stanford University found that black men were four times more likely than whites to be searched during police traffic stops and were more likely to be handcuffed even if they were not arrested.

Last month, the police chief in neighboring San Francisco also resigned over pressure from a number of high-profile killings by the hands of law enforcement officers there.

The city’s police chief Greg Suhr had faced mounting criticism and protests for months in the wake of several high-profile police killings and a racist text scandal.