Mr Van Hauwermeiren said there had been "a lot of lies and exaggerations" about his time in Haiti. "I shall react... Many people, including in the worldwide media, will blush hearing my version of facts", van Hauwermeiren was quoted as saying by the Het Nieuwsblad newspaper. There are things which have been described correctly. I could see that they gave scrupulous thought to how to help and empower the world's most vulnerable people.
"Parties every week? Fancy villas? It hurts", the 68-year-old told newspaper De Standaard. "Everything I see everywhere is hard to bear and pains me".
Oxfam has since confirmed it dismissed Mr van Hauwermeiren's replacement as Haiti director a year ago amid allegations of "inappropriate behaviour".
Oxfam sex scandal prompts 'disappointed' Tutu to step down as ambassador
Oxfam has since faced further allegations prostitutes were also used by staff in Chad in 2006, where Mr van Hauwermeiren was the charity's country chief at the time.
Archbishop Emeritus Desmond Tutu has stepped down as an ambassador for Oxfam, citing disappointment at the British aid agency's embroilment in a sex scandal involving staff in Haiti after a massive 2010 quake.
A scandal over sexual abuse in the foreign aid industry that began with Oxfam spread on Wednesday, as French group Doctors Without Borders revealed it had fired 19 staff a year ago for harassment or abuse.
The charity said the allegations that under-age girls may have been involved were not proven.
Aid group Doctors Without Borders said it had acted on 24 cases of harassment or sexual abuse previous year as British charity Oxfam faces a storm over its handling of a sex scandal.
Several sponsors and partners of Oxfam including Visa and the retail chain Marks and Spencer have also said they are examining the situation.
But it stressed the dismissal of Damien Berrendorf, who served as the Oxfam's country director in Haiti from 2012 to 2017, was "not related to sexual misconduct" and was "not connected to the case in 2011".
It said in a statement that it had acted on 24 of these cases, firing 19 employees as a result.
International Development Secretary Penny Mordaunt is considering whether to stop the charity's aid funding in the wake of the scandal, which has prompted an statutory inquiry by the Charity Commission.
Ms Mordaunt said: "No organisation is too big, or our work with them too complex, for me to hesitate to remove funding from them if we can not trust them to put the beneficiaries of aid first".
The minister, who said a culture change is needed, is due to meet the National Crime Agency on Thursday after talks with charity bosses, regulators and experts in recent days.