GENEVA — Independent experts looking into allegations of sexual harassment at the U.N. agency that fights AIDS say it is plagued by "defective leadership," a culture of impunity, and a toxic working environment that cannot be changed unless its top official is replaced.

In a damning new report released Friday, the four experts cited a "vacuum of accountability" and said UNAIDS leaders had failed to prevent or properly respond to allegations of sexual harassment, bullying and abuse of power.

The panel was created earlier this year following allegations of sexual harassment by staffers and calls from critics for executive director Michel Sidibe of Mali to resign.

Sidibe has denied claims that he tried to force an employee to drop allegations that she was sexually assaulted by his former deputy. And despite the scathing report, Sidibe said in a statement that he is the right man to turn around the organization.

That is not what the investigators believe.

"The panel has no confidence that the current leadership can deliver cultural change when that leadership has been largely responsible for the current malaise," the report said. Its authors interviewed or received written submissions from more than 100 staffers and conducted a survey of about 60 percent of the agency's staff.

Just as the report was made public, UNAIDS issued a statement promising an "agenda for change" led by the 66-year-old Sidibe to build upon the recommendations of the panel.

"I have taken on board the criticisms made by the panel," Sidibe said, "In proposing this agenda, I am confident that we can focus on moving forward."

He said he would spend a year making UNAIDS a workplace "where everyone feels safe and included."

Despite its searing critique, the panel noted Sidibe's "outstanding contribution" to UNAIDS' work and called him a "passionate and effective advocate" for the world's most vulnerable people. It said he had "spoken bravely" about the risks of HIV/AIDS among adolescent girls and women.

The UNAIDS chief is appointed by the U.N. secretary-general, who has the power to replace him. The independent panel's report will be presented to the UNAIDS board next week.

U.N. spokesman Stephane Dujarric said Sidibe would "continue to create a model working environment for all staff," ensuring safety and inclusivity. He deferred to the UNAIDS board for any action that might be taken.

"We await their deliberations," he said.

UNAIDS spokeswoman Sophie Barton-Knotts said Sidibe "is fully aware that there is a lot of work to do — across all levels of the organization — and he is determined to lead that transformation."

The panel, however, disagreed. It found solutions proposed by Sidibe to be "superficial and insufficient." It also slammed Sidibe for failing to take responsibility for the organization he has led for the past eight years, saying his proposed changes "demonstrate a lack of insight into the magnitude of the problems."

According to the survey conducted by the panel, nearly 4 percent of staffers reported having experienced some form of sexual harassment in the past year and more than 40 percent reported having suffered some abuse of authority.

Numerous staffers complained the agency was run like a patriarchy, with little oversight and retaliation against staffers who spoke out.

One staffer described a meeting where Sidibe "boasted" he had personally ensured the appointment and promotion of his African "brothers."

"UNAIDS is like a predators' prey ground," wrote another interviewee. "You can use promises of jobs, contracts and all sorts of opportunities and abuse your power to get whatever you want ... I have seen senior white male colleagues dating local young interns or using UNAIDS resources to access sex workers."

Such problems began spilling into the public spotlight after UNAIDS staffer Martina Brostrom went public earlier this year with allegations originally laid out in a sexual harassment and assault complaint in 2016. In it, she alleged that Luiz Loures, once the agency's deputy director for programs, had forcibly kissed and grabbed her in a Bangkok hotel elevator in May 2015 — claims Loures denied. He left UNAIDS earlier this year.

The World Health Organization office that investigated the case concluded that there was insufficient evidence to support Brostrom's claims.

Brostrom told The Associated Press she was still going over the experts' 73-page report, but added she was "pleased that the truth ... is finally out."

The Associated Press does not identify typically victims of sexual assault. However, Brostrom spoke to the news media this year after a WHO panel accepted the investigators' recommendation to close the case.