The fate of UNAids chief Michel Sidibe hung in the balance on Tuesday as he faced the agency's oversight body after an expert report blasted his leadership and called for his removal.
The organisation founded to coordinate the global response to the HIV/Aids epidemic has been plunged into a crisis unprecedented in its 24-year history.
Seeking to ease concerns after UNAids was accused of mishandling sexual assault allegations against a former deputy chief, Mr Sidibe initiated the Independent Expert Panel report to study the agency's culture and propose reforms.
A stunning rebuke
But the findings released last week were a stunning rebuke of the Malian national's nine-year tenure.
It said UNAids was "broken" due to "defective leadership" and accused Mr Sidibe of overseeing a work environment that tolerated sexual harassment and abuse where a "cult of personality" surrounding the executive director saw benefits doled out as favours by Mr Sidibe and his cadre of top allies.
It also said Mr Sidibe "accepted no responsibility" for anything that has gone wrong under his watch.
"For... UNAids to regain a culture of dignity and respect, a change in leadership has become necessary," the report said.
UNAids' oversight body, the Programme Coordinating Board (PCB), opened a three-day meeting in Geneva on Tuesday that may decide Mr Sidibe's fate.
With activists demanding immediate change, pressure is mounting on UN chief Antonio Guterres to act.
"What is the point of having an independent investigation if you don't intend to do anything about the findings?" the head of the Aids Healthcare Foundation, Mr Michael Weinstein, told AFP.
Mr Weinstein, who leads the world's largest HIV/Aids organisation, stressed that the panel's conclusions were "unequivocal," and that if the Mr Guterres does not act soon "it would truly be a shocking dereliction of duty".
Hours after the report's release, Mr Guterres's spokesman Stephane Dujarric noted that Mr Sidibe had pledged "to create a model working environment for all staff".
The UN chief would reserve comment until the PCB "deliberations" were complete.
Code Blue, a pressure group that has been at the forefront of exposing the rot at UNAids, blasted that response as "astonishing".
"What does it take to be fired by the United Nations?" it said.
UNAids on Friday said that Mr Sidibe has no intention of resigning.
The executive director, accused of fostering a "patriarchal culture" where staff do not report sexual misconduct because they fear inaction or retaliation, said in a statement that he had been "inspired by the #MeToo movement".
"I have taken on board the criticisms made by the Panel...I will spend the next 12 months implementing this agenda for change," Mr Sidibe said.
The editor of the influential medical journal The Lancet, Mr Richard Horton, called Mr Sidibe's response "surreal".
"Nowhere does (Sidibe) accept that he was responsible for the toxic work environment that his leadership created. Nowhere does he acknowledge the grievous harms done to his colleagues at UNAids," Mr Horton wrote in an online commentary.
"Both the PCB and Antonio Guterres now have a duty to deliver on the recommendations of the Expert Panel" and fire Mr Sidibe, he added.
"The reputation of UNAids and the UN system depends on it."
It is not yet clear if the PCB will make a formal recommendation on Mr Sidibe's future.
UNAids spokeswoman Sophie Barton-Knott told AFP that the panel report would be an important subject at the closed-door PCB meeting.
Britain, which chairs the PCB, said it "cannot tolerate" the practices detailed in the report.
"We expect immediate and far-reaching action from UNAids over this to address the findings," a spokesperson for the Department for International Development (DFID) told AFP in an email.