By Stephanie Nebehay GENEVA (Reuters) -The World Health Organization, facing pressure from donors, said an independent investigation into allegations of sexual abuse in Democratic Republic of Congo against WHO aid workers should issue findings by the end of August. The Thomson Reuters Foundation reported last October that more than 50 women had accused aid workers from the WHO and leading charities of sexual exploitation and abuses during the Ebola outbreak. WHO Director-General Tedros Adhanom Ghebreyesus told its annual ministerial session that some states were frustrated by the pace of the inquiry. The allegations undermine trust in WHO and threaten the critical work we are doing , he said on Friday. The independent commission set up its base in Goma in March and hired an investigative firm JRR that began field investigations in early May, Tedros said. Despite security challenges in Congo's North Kivu region and the volcanic eruptions in the past week, he said: The team is doing its best to complete its work in time for the Commission to deliver its report by the end of August 2021 . Canada's WHO ambassador, Leslie Norton, read out a statement on behalf of more than 50 countries, including the United States, Japan and European Union member states, urging the WHO to speed up the investigation and provide an update in June. The allegations of sexual abuse and harassment were discussed at a meeting last week with WHO officials, she said. We expressed alarm at the suggestions in the media that WHO management knew of reported cases of sexual exploitation and abuse, and sexual harassment, and had failed to report them, as required by U.N. and WHO protocol, as well as at allegations that WHO staff acted to suppress the cases, Norton said. The U.N. agency should ensure that appropriate disciplinary action is taken where allegations are substantiated , she said. A report by WHO's external auditor, presented on Friday, said that there were 14 cases of sexual misconduct implicating WHO employees last year, including the Congo case, compared with 11 in 2019. “The number of complaints or reports of misconduct are a reflection of the ethical climate of an organization and its ‘tone at the top’, the report said, and therefore, an increasing trend of such complaints should be a cause of concern for the management. British Ambassador Simon Manley told the talks: We must from now on see much more transparency from the WHO. (Reporting and writing by Stephanie Nebehay; additional reporting by Emma Farge; editing by Mark Heinrich)