One would expect that humanitarian workers take care of the people urgently in need of assistance during and following a crisis. But the image of the altruistic aid worker is too often a myth, because anyone who is in the position to help others is the one wielding the power - and some take advantage of it.

Staff members of Britain's nongovernmental organization Oxfam allegedly organized orgies with prostitutes in the organization's villa after the devastating earthquake in Haiti in 2010. But the scandal doesn't stop there. Sex parties were reportedly also held during relief missions in Chad in 2006. Oxfam staff members apparently even raped women in South Sudan.

It is not the first sex scandal that has shaken the world of international aid, according to Burkhard Wilke, managing director of the German Central Institute for Social Issues (DZI).

"Employees or partners of aid organizations in aid regions have repeatedly made themselves complicit in the sexual exploitation of the local population," he told DW.

Read more: Oxfam sex scandal: EU warns charities to uphold 'ethical standards'

The medical aid organization Medicins Sans Frontieres (Doctors Without Borders) recently reported 24 cases of abuse or sexual harassment in the past year. The International Rescue Committee (IRC) admits that there have been three cases of sexual abuse during operations in the Democratic Republic of Congo.

Brothel in the Balkans

Cases of aid worker misconduct reach back to the Yugoslav wars in the 1990s. International aid workers were involved in the sexual exploitation of girls and women during the wars in the Balkans. UN blue helmet soldiers and humanitarian workers were all said to have visited prostitutes on a regular basis.

The German women's rights organization Medica Mondiale helped traumatized women in Bosnia during the Balkan conflict, and the Cologne-based NGO still helps girls and women in war and crisis regions.

Ara Stielau, Medica Mondiale's director of the international programs, said the aid worker scene regarded visits to prostitutes during missions as a "trivial offense and private pleasure." Stielau said she still remembers the words of a German aid organization's executive when he was confronted with the sexual misconduct of some of his employees. He apparently replied, "I can't watch what my men are doing between the sheets."

Inhibitions are lower

Economic hardship is among the reasons why women in crisis regions work as prostitutes. Women often suffer so much that they lose their inhibitions and are willing to accept food or money for sex, Stielau said. That is how local women in need of help can become dependent on male aid workers from abroad who ultimately have resources and the power to distribute relief supplies.

"Employees of an organization have money and thus the power to help one person and not another - and that creates temptation," Wilke added.

Most international aid organizations are aware of these dangers and have put in place special codes of conduct for all employees.

"However, the Oxfam case reveals that the necessary consequences are not always drawn when it comes to sexual misconduct," Wilke said.

A trust crisis

"Using the services of prostitutes may not necessarily be against national laws, but it violates all codes of conduct issued by relief organizations," Wilke said, adding that organizations risk losing their reputation if their employees are caught acting immorally.

That loss of trust can be a huge problem, as credibility is key in the world of international charity. NGO aid organizations depend on donations — and on the trust of donors, who want to know that their money is going to the people who need it.

For this reason, Wilke said misconduct should be reported "unsparingly" to the public. Transparency is the top priority. In Germany, Wilke's institute awards a seal of approval to organizations for ethical and transparent work. In the event of misconduct, NGOs may lose the seal of approval.