The charity says it is meeting with the government of Haiti to "apologise for our mistakes"
Oxfam has released a report from 2011 into allegations of sexual misconduct by workers in Haiti.
The British-based charity's internal report focuses on claims that staff used prostitutes on the organisation's property, as well as allegations of sexual harassment of staff, fraud, negligence and nepotism.
It alleges that Roland Van Hauwermeiren, the then director of operations in Haiti, admitted using sex workers in his charity-funded accommodation and was granted a "phased and dignified exit".
BBC has previously reported that Mr Van Hauwermeiren has denied paying for sex.
The 10-page report also alleges that three of the suspects - whose names have been redacted - physically threatened or intimidated a witness during the investigation, resulting in further charges of bullying and intimidation.
According to the report: "None of the initial allegations concerning fraud, nepotism, or use of under-age prostitutes was substantiated during the investigation, although it can't be ruled out that any of the prostitutes were under-aged."
The investigation ultimately resulted in four dismissals and three resignations.
In a statement, Oxfam said it was making the "exceptional publication" of the report in order to be "as transparent as possible" about the decisions made during the investigation.
Winnie Byanyima, Oxfam International’s Executive Director, said: “Oxfam is urgently committed to act upon the moral responsibilities we have towards women in Haiti. We are also meeting with the government of Haiti to apologise for our mistakes and discuss what more we can do.
"It is vitally important we re-examine what happened, and learn from it."
The British branch of Oxfam has been rocked by the allegations in recent weeks, and has agreed to withdraw from bidding for any new UK government funding until government officials are satisfied the charity can meet the "high standards" expected.
Several senior officials with the international charity have resigned in the wake of the controversy, including the deputy chief executive of Oxfam Great Britain.
An 'urgent and independent' review of Oxfam's culture and practices has been announced, and will be lead by prominent women's rights experts.
The charity is also introducing a number of immediate measures - including creating a new global database of accredited referees to combat 'unreliable' references by past or current staff, and extra resources for the charity's safeguarding processes.
Oxfam Ireland has pledged to play a 'leadership role' in the reform process for the international charity.
No staff employed by Oxfam Ireland were involved in the Haiti case, the Irish branch has said.