The Oxfam employee at the epicenter of a sexual misconduct scandal in Haiti, Ronald van Hauwermeiren, had a track record known to the organization.

On Wednesday, van Hauwermeiren, 68, rejected many of the allegations as “lies and exaggerations,” warning that international media will feel shame as he tells his side of the story, the Belgian newspaper Het Nieuwsblad reported.

Van Hauwermeiren admits to “some mistakes,” but claims he only had one intimate relationship with a Haitian woman that was not a prostitute.

Van Hauwemeiren has been among a number of employees sacked in 2011 over sexual misconduct while delivering aid to Haiti; but he was re-hired by the same charity in Ethiopia. He also faced similar allegations during his work in Chad and Liberia. Oxfam has since described the decision to re-hire van Hauwemeiren as a “serious error” and is conducting an internal investigation into vetting and recruitment processes.

The Times have accused the 68-year old former Oxfam employee of organising sex parties in a villa hired by Oxfam in Haiti.

The scandal has undermined Oxfam’s international prestige, with Archbishop Desmond Tutu, Hollywood star Minnie Driver, and Senegalese singer Baaba Maal resigning from their role as ambassadors of the organisation. More than a thousand people have cancelled direct-debit donations to the organization since the scandal erupted.