It started with allegations of sexual abuse by six French peacekeepers. Now the UN is inundated with claims against troops in the Central African Republic.
What are the allegations?
There are more than 100 abuse cases, but the most significant involved six French soldiers who are accused of sexually abusing minors near a camp for internally displaced people in Bangui, the capital city of the CAR.
It is alleged that the troops asked children to perform sexual acts in exchange for food.
Since these claims first surfaced, there have been hundreds of other sexual abuse allegations against UN peacekeepers from other countries on this mission.
Why were the French troops there?
They were deployed to the CAR between December 2013 and June 2014 to protect civilians at the height of the clashes between the Muslim Seleka rebels and mainly Christian militia.
The troops, known as the Sangaris force, were part of a joint mission along with the UN's Multidimensional Integrated Stabilisation Mission in the Central African Republic (MINUSCA) that started in 2014.
How did the issue surface?
UN official, Anders Kompass, sent an internal report collected by colleagues in the CAR to French prosecutors because he was concerned the UN was not taking any action.
The report contained interviews with children conducted in 2014 by staffers from the Office of the UN High Commissioner for Human Rights and the United Nations Children's Fund (UNICEF).
Kompass who was the director of field operations at the UN human rights office in Geneva said he went to the French because the UN did not.
How did the UN respond to the allegations?
After Kompass' claims, the UN launched an independent investigation, "Taking Action on Sexual Exploitation and Abuse by Peacekeepers", in December 2015.
"Information about the allegations was passed from desk to desk, inbox to inbox, across multiple UN offices," the investigation found.
It also says that even when the French government sought UN cooperation, the requests "became bogged down in formalities" and stuck to protocols on whether the report was given to the French government following UN regulations.
The investigation found that the children were assaulted mainly by French soldiers, with cases of abuse dating back to December 2013.
What is the latest on the case?
The Paris prosecutor is investigating whether to pursue legal action against the soldiers.
An earlier investigation by three French judges decided not to charge them. The soldiers said they gave the children food but not in exchange for sexual acts.