Oxfam, one of the world’s most prominent relief agencies, could lose its funding from the British government over reports that its workers exploited survivors of a massive earthquake in Haiti, and possibly other disasters, for sex.

It is a “complete betrayal of both the people Oxfam were there to help and also the people that sent them there to do that job,” Britain’s international development secretary, Penny Mordaunt, told BBC News, which noted that the nonprofit received $44 million in government funds last fiscal year.

Mordaunt spoke Sunday — three days after a Times of London investigation accused Oxfam’s then-director in Haiti, along with other workers, of running an illegal makeshift brothel after a 2010 quake devastated the country.

Oxfam has admitted to at least some of the wrongdoings alleged in the report, and the organization has promised an internal review and overhaul. “We are ashamed of what happened,” the nonprofit’s chair wrote in a statement Sunday. “We apologize unreservedly.”

But contrition may not be enough. The Times alleged that Oxfam tried to hide the years-old allegations from the public, letting its country director in Haiti quietly resign rather than firing him after he admitted to using prostitutes.

And the Guardian reported new accusations over the weekend: that the same man,

, was also accused of hiring sex workers in Chad.

[Haitians are desperate for help. But they don’t want it from the American Red Cross.]

Mordaunt told BBC that she would meet with Oxfam officials Monday, but she sounded unimpressed by the nonprofit’s promises to reform.

“If the moral leadership at the top of the organization isn’t there, then we can’t have you as a partner,” she said.

The Times’s report was based on sources familiar with the organization’s work in Haiti around that time as well as a report summarizing an internal Oxfam investigation into the allegations.

Oxfam was in the midst of a large effort on the island after the quake, which killed more than 200,000 people and left many more injured and displaced. The charity had a fund worth more than $100 million to provide relief supplies and help rebuild Haiti’s infrastructure, the Times reported.