Roland van Hauwermeiren, who has become the focus of a sex scandal engulfing the charity, spoke out in an interview with local media in his native Belgium.
"What I see being published everywhere, is hard to bear. It hurts," the 68-year-old reportedly told newspaper De Standaard from his apartment on the Belgian coast.
"But you should know that a lot of people, including in the international media, will blush with shame when they hear my version of the facts.
"It is not that I deny everything. There are things which have been described correctly. But there are many lies and exaggerations.
"Parties every week? Fancy villas? Women paid with money from the organisation?"
Mr van Hauwermeiren added his family "no longer want to see me", while he would respond through his lawyer in due course, the newspaper reported.
Sky News has also seen a letter sent by Mr van Hauwermeiren to Belgian TV channel VTM, in which he addresses specific allegations made against him during his time working in Liberia, Chad and Haiti.
Writing in Dutch, Mr van Hauwermeiren appears to deny any contact with prostitutes, the inappropriate use of aid funds, or the notion of sex parties in any of the three countries.
He also seems to suggest the source of the allegations may have a vengeance against him.
Last week, The Times reported senior aid workers used prostitutes in Haiti in 2011 amid an international response to the Caribbean nation's devastating earthquake.
An internal investigation by the charity into sexual exploitation did not prove allegations underage girls were involved, Oxfam said.
Mr van Hauwermeiren is said to have resigned before the end of Oxfam's investigation into the Haiti allegations, with the charity having reportedly offered him a "phased and dignified exit" after he admitted using prostitutes.
Oxfam has denied a cover-up of the 2011 allegations, following claims it did not sack Mr van Hauwermeiren in order to avoid reputational damage.
The charity has also come under fire after it was said they did not pass on information about Mr van Hauwermeiren's resignation to a French charity, which later employed him in Bangladesh.
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.
Bosses admitted failing to act "adequately" on the behaviour of Oxfam staff in both Chad and Haiti.
Oxfam has confirmed it dismissed Mr van Hauwermeiren's replacement as Haiti director last year amid allegations of "inappropriate behaviour".
However, the charity stressed the sacking "was not related to sexual misconduct and was not connected to the case in 2011".
On Wednesday, The Times alleged Mr van Hauwermeiren, a former Belgian army officer, also had "young girls" visit his house in Liberia when working in the African country in 2004 for a different charity.
Oxfam received £31.7m from the UK Government in 2016/17.
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 will meet with the boss of the National Crime Agency on Thursday in response to Oxfam's crisis.
Oxfam would not respond to the remarks Mr van Hauwermeiren made to Belgian media.
The charity has previously described itself as "ashamed" of what happened in Haiti, although it has neither confirmed or denied specific allegations made by The Times.
Source : https://news.sky.com/story/oxfams-shamed-ex-haiti-chief-roland-van-hauwermeiren-hits-back-at-lies-11251452