Oxfam has suspended two staff members in the Democratic Republic of Congo over allegations of sexual exploitation and bullying.
The charity said the claims were uncovered as part of an investigation it set up in November.
However, concerns about misconduct in the central African country date back to 2015, according to whistleblowers.
Oxfam was at the centre of a major scandal in 2018 when claims emerged about the use of sex workers by senior aid workers in Haiti.
It had been in the Caribbean country following the devastating 2010 earthquake that killed around 220,000 people.
Thousands of people cancelled their donations in the wake of the scandal and Oxfam had to make £16m of cuts.
The Charity Commission’s report found it "had a culture of tolerating poor behaviour and… failed to meet promises made on safeguarding, ultimately letting everyone down".
However, last month the commission said Oxfam had made "significant improvements on safeguarding" and it can now bid for UK government money again.
In a statement on the new allegations, Oxfam said: "We can confirm we have suspended two members of Oxfam staff in the Democratic Republic of Congo as part of an ongoing external investigation, which we set up last November, into allegations of abuses of power, including bullying and sexual misconduct.
"The Charity Commission were notified at the start of the investigation and we have kept them informed about its progress.
"We are acutely aware of our duty to survivors, including in supporting them to speak out safely. We are working hard to conclude the investigation fairly, safely and effectively."
Oxfam said it was not releasing the names of the individuals suspended to protect people, including witnesses and survivors, and to avoid jeopardising the investigation.
The charity has been in Democratic Republic of Congo since 1961 and is involved in sanitation, emergency food and clean drinking water projects.