An investigation by The Times revealed that several Oxfam staff had used sex workers while delivering aid following the natural disaster seven years ago. The newspaper alleges some of those prostitutes may have been underaged.
Beyond the damage to Oxfam as an organization, it is unclear if those involved in prostitution or sexual crimes on their missions will face consequences. It now consists of 19 separate worldwide committees, and is one of the largest aid federations in the world.
Leaders including Oxfam's chief executive Mark Goldring (left) knew about allegations of rape and other widespread sexual misconduct, according to a former worker..
"We take a zero tolerance approach to any allegations of misconduct by organisations that receive our funding".
In her interview, Evans also said that she faced "a continual fight" to get more resources from the charity for her safeguarding team, but said her pleas were ignored.
"As programme director at the time, I am ashamed that this happened on my watch, and I take full responsibility".
"We are ready to review and, if needed, cease funding to any partner who is not living up to the required high ethical standards", said European Commission spokeswoman Maja Kocijancic. "It is now clear that these allegations-involving the use of prostitutes and which related to behavior of both the country director and members of his team in Chad-were raised before he moved to Haiti".
Oxfam's deputy chief executive last night resigned after the Development Secretary Penny Mordaunt hauled in the already under fire charity's bosses. "There was an exploration of how should the organization respond but we didn't act on it".
Search and Rescue workers make their way through a devastated neighborhood in Haiti during 2010.
Haiti leader: UK aid workers violated 'basic human decency'
"Following concerns raised in this article, the staff member has been put on leave while we examine the issues raised and follow our Code of Behavior protocol to determine next steps", Bain said.
The British Government has now threatened to cut aid funding to charities that fall short on safeguarding and do not cooperate with authorities investigating alleged sexual abuse.
Such information sharing is especially important in the global aid sector. Different aid groups often must rely heavily on the recommendation letters received from previous employers when making hiring decisions.
Asked about foreign aid charities in general, 53% said they were trustworthy, while 47% said they were untrustworthy.
Allegations in the report included repeated allegations of rape in South Sudan, and a woman who was a beneficiary of Oxfam aid coerced into having sex to receive it.
Another Catholic global aid agency, Trócaire in Ireland, said it was "horrified" by the recent reports from Haiti.
"In the 21st century, it is utterly despicable that sexual exploitation and abuse continues to exist in the aid sector".
The secretary of state also said Oxfam had made a "full and unqualified apology" over the failures of the organisation.
Ms Mordaunt said: "I know people will be anxious about the charity, they'll be anxious about the money, but we need to be guided by what the Charity Commission are doing and also I have made it very clear to Oxfam what we expect to see from them".