LONDON — Claims that aid workers with the British charity Oxfam hired prostitutes in Chad were raised more than a decade ago, but the official in charge there was allowed to remain with the charity and moved on to Haiti, where the pattern continued, the group acknowledged on Monday, as one of its top executives stepped down.
The resignation of the charity’s deputy chief executive, Penny Lawrence, was unlikely to quell growing outrage over revelations about the conduct of aid workers in desperately poor countries. Oxfam’s leaders met on Monday with the British cabinet minister for international development, who has raised the prospect of cutting off its government funding.
Oxfam is one of the private groups that the British government relies on most heavily to carry out humanitarian and economic development projects around the world. With more than $ 550 million in annual spending, 5,000 employees and 27,000 volunteers, it is one of the largest British charities.
On Friday, the British newspaper The Times of London revealed that Oxfam officials doing earthquake recovery work in Haiti in 2011 had hired prostitutes, but that the charity had not made that fact public. Then came allegations on Sunday that Oxfam staff members in Chad did the same thing in 2006, under the same Oxfam country director, Roland van Hauwermeiren, who would be in charge in Haiti five years later.
“We have become aware that concerns were raised about the behavior of staff in Chad as well as Haiti that we failed to adequately act upon,” Ms. Lawrence said in a statement announcing her resignation. “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.”
“As program director at the time, I am ashamed that this happened on my watch and I take full responsibility,” she said.
In just a few days, the news about Oxfam has turned into a much wider uproar about exploitation by aid workers in some of the poorest parts of the world, and a culture among charities and governments that has shielded them. Over the weekend, The Sunday Times of London reported that internal accounting by several British aid groups showed that more than 120 workers had been accused of sexual abuses in the past year.
In an essay in The Telegraph, Priti Patel, formerly the international development secretary in the current government, charged that the scandal at Oxfam was just “the tip of the iceberg,” and that British officials who distributed aid around the world had refused to act on claims of sexual exploitation, including that of children. Ms. Patel said the government should cut off groups that failed to stop such abuses.
The revelations play into arguments by some Conservative lawmakers that Britain, struggling to finance its health care system, should drastically scale back its foreign aid. Just as the first reports about Oxfam misconduct surfaced, Jacob Rees-Mogg, a Conservative member of Parliament who is seen as a potential rival to Prime Minister Theresa May, delivered to her a petition from The Daily Express, which the newspaper said was signed by 100,000 of its readers, demanding foreign aid cuts.
In 2011, Oxfam stated that it had found misconduct by some of its workers in Haiti, where the group was taking part in recovery efforts after a devastating earthquake, and that those people had left the organization. But Oxfam did not specify who was involved or what they had done wrong, and, as it now concedes, it did not inform the police in Haiti.
Last week, The Times of London reported that the misconduct included hiring prostitutes, pressuring Oxfam’s drivers to procure prostitutes and holding sex parties at the group’s houses. The organization fired four people and allowed three others, including Mr. van Hauwermeiren, to resign while under investigation.
Oxfam acknowledged on Friday that there had been sexual misconduct, and that Mr. van Hauwermeiren was among those who left over the matter, but it has not named the others.
It said its investigation in Haiti, where prostitution is illegal and the legal age of consent is 18, was not able to prove or disprove allegations that some of the Haitians hired were under 18. There have been no claims that Oxfam workers demanded sex in return for aid, an allegation that has at times been made against other groups.
Haiti’s ambassador to Britain, Bocchit Edmond, told the BBC that his government would demand that Oxfam name the officials involved in the episode and turn over its investigative files, “so all legal actions will be taken against those who committed those crimes.”
The group has apologized repeatedly, and it said that the behavior of some of its staff members in Haiti had led years ago to tougher policies and safeguards, but it has also insisted that it did not engage in a cover-up.
Oxfam has said that in 2011, it shared its findings with the Charity Commission, a British government agency, which took no action. But the commission’s chief investigator said that it was not told the full extent of the misconduct, and that it would have acted differently if it had been.
A breach with the government would be a serious blow to Oxfam, particularly if its private fund-raising also suffered because of the revelations. In its last fiscal year, the group received 10 percent of its revenue from the British government, 6 percent from other national governments and 16 percent from multinational organizations like the United Nations and the European Union.
Private and governmental aid groups mobilized in Haiti after the January 2010 earthquake, but relief efforts have been tarnished by charges of misconduct, including reports of money being misspent and misleading fund-raising by some charities. A cholera outbreak that killed thousands of people in Haiti was traced to peacekeeping troops sent by the United Nations after the earthquake.