A report alleges that Syrian women in refugee camps have been forced to give sexual favours in return for aid from the United Nations.
The report, entitled 'Voices from Syria 2018', was published by the United Nations Population Fund (UNFPA), which conducted research on violence against women in the war-torn region.
It claims that UN aid workers would often harass and abuse women at distribution sites, to the point where some female refugees felt they could no longer go there for humanitarian aid.
Some women were allegedly forced into short-term marriages with officials from the UN and other charities, and would have to provide "sexual services" in exchange for meals.
Aid distributors reportedly engaged in inappropriate behaviour with women in refugee camps, such as asking for their phone numbers or driving them home to "take something in return".
The report quoted one teenage girl from Idlib, northern Syria, as saying: "The more the girl gives to the distributor, the more aid she will receive."
A similar 2015 survey by the International Rescue Committee (IRC) suggested similar abuse of power was happening then, but the UN failed to take significant action.
IRC said 40 percent of those interviewed said they had witnessed or experienced sexual violence while accessing humanitarian aid in southern Syria.
The reports have questioned the ethics of aid workers in developing and war-torn countries, especially after it was revealed that Oxfam workers hired prostitutes during the 2010 Haita earthquake.