A history of NGO sex abuse accusations
British charity Oxfam, reeling from claims of sexual assault and rape by its workers in Haiti and South Sudan, is not the first non-governmental organisation to be accused of abuse.
Previous revelations spurred the United Nations in 2002 to issue special measures for all its staff and others, including aid workers under UN contract, based on a policy of zero tolerance.
"The involvement of humanitarian workers in acts of sexual exploitation and abuse is a grave violation of our responsibility to do no harm and to protect people affected by crises," said the UN's Humanitarian office OCHA.
Alleged abuse in West Africa
The issue came to public attention in 2002 after allegations of widespread abuse of refugee and internally displaced women and children by humanitarian workers and peacekeepers in West Africa.
In refugee camps in Guinea, Liberia, and to a lesser extent Sierra Leone, dozens of male aid workers, often locals, were suspected of having exchanged money or gifts for sex with young refugee girls aged between 13 and 18.
"It's difficult to escape the trap of those (NGO) people, they use the food as bait to get you to have sex with them," an adolescent in Liberia was quoted as saying in a report from the UN refugee agency.
More than 40 agencies and organisations and nearly 70 individuals were mentioned in the testimonies taken from 1,500 children and adults for the UN report, which the body stressed could not be verified.
Ron Redmond, spokesman for the United Nations High Commissioner for Refugees (UNHCR) indicated that similar concerns existed in other countries, but to a lesser degree.
Save the Children sounds alarm
In a 2008 report, NGO Save the Children said "children as young as six are trading sex with aid workers and peacekeepers in exchange for food, money, soap and, in very few cases, luxury items such as mobile phones."
Its findings were based on work with hundreds of youngsters from Ivory Coast, southern Sudan and Haiti.
The report also highlighted instances of rape, verbal sexual abuse, child pornography and prostitution and trafficking of youngsters, many poor, displaced or orphaned by conflict.
The United Nations has also been damaged by a wave of rape cases involving soldiers on peacekeeping missions, ranging from the Central African Republic to Haiti and the Democratic Republic of Congo and Ivory Coast.