The deputy head of UNAIDS, accused of sexually assaulting a female colleague but cleared of wrongdoing by an internal United Nations probe, announced his decision to step down on Friday.
Luiz Loures "has communicated his wish to the UNAIDS executive director not to seek the renewal of his position," the agency said in a statement.
Loures, a Brazilian national, "will end his term as deputy executive director at the end of March 2018," it added.
UNAIDS spokesman Mahesh Mahalingam told reporters in Geneva that Loures's decision had no connection to the allegations against him, noting the findings of the internal UN probe.
A junior female colleague filed a formal complaint alleging that Loures sexually harassed her beginning in 2011 and sexually assaulted her in a lift at a Bangkok hotel in 2015, where UNAIDS was hosting a major conference.
The internal probe conducted by the World Health Organization's Office of Internal Oversight Services (IOS) said there was insufficient evidence to support the allegations.
But activists and a legal expert have questioned the credibility of the investigation, insisting that important circumstantial evidence was not taken into account.
UNAIDS chief Michel Sidibe was faulted by the IOS for trying to settle the dispute quietly even as an official probe was underway.
Loures's decision to step down comes a day after UNICEF's deputy director Justin Forsyth resigned from the UN children's agency following complaints of inappropriate behaviour towards female staff in his previous post as head of British charity Save The Children.