Major worldwide charity Oxfam is in hot water with the British government for having sex parties with Haitian prostitutes following the 2010 natural disaster that rattled the nation, killing 220,000 people.
Charities doing overseas aid work will lose funding if they fail to cooperate over safeguarding issues, warned the worldwide development secretary.
Oxfam has been accused of trying to cover up allegations of sexual misconduct by workers in Haiti in 2011.
Ms Mordaunt's announcement comes as the Observer reports that Oxfam workers allegedly used prostitutes in Chad in 2006.
Ms Mordaunt will meet senior staff at Oxfam today and the Charity Commission has written to them, as a "matter of urgency", requesting further information.
A spokesperson for Oxfam said the organisation was deeply shocked by the new allegations, admitting the problem was "sector-wide".
The International Development Secretary Penny Mordaunt revealed she was writing to the charities to insist they spell out what steps they are taking on the issue and confirm they have referred all concerns about specific cases and individuals to the relevant authorities.
"The hundreds of thousands of people that support Oxfam every month are compromised by this, and to everybody I do apologise".
"What is so disturbing about Oxfam is that when this was reported to them, they completely failed to do the right thing", she said.
"We want to see Oxfam provide all the evidence they hold of the events to the Charity Commission for a full and urgent investigation of these very serious allegations".
"It is utterly despicable that sexual exploitation and abuse continues to exist in the aid sector", Ms Mordaunt said.
"If the moral leadership at the top of the organisation isn't there, we can not have you as a partner", she said.
MPs have warned about "predatory paedophiles" following sexual assault allegations against more than 120 workers for British leading charities.
The charity added it will soon deliver a "safeguarding training course for faith organisations, especially churches, so they can understand, recognise and respond to safeguarding issues, and develop a safer culture".
It announced on Sunday that one investigation led to the dismissal of a staff member, while the other case resulted in disciplinary action (not dismissal).
Oxfam's boss say he is "deeply ashamed" over accusations its staff used prostitutes in Haiti in the aftermath of the 2010 quake.
Oxfam said four members of staff were dismissed and three, including the country director, were allowed to resign before the end of the investigation.
Oxfam has denied that they took part in any coverup thought according to reports they did not let the Haitian government what was happening which meant they were unable to take legal action against the employees involved.