The United Nations is investigating more than 90 cases of peacekeeper sexual abuse in the Central African Republic, including an incident in which a French military commander allegedly had four girls tied up and forced them to have sex with a dog, according to a new report by an activist group.

AIDS Free World, the same group that last year leaked initial reports of sexual abuse carried out by French and African forces in the country, said that the most recent incident occurred this Monday, when a Congolese peacekeeper allegedly raped a 16-year-old girl in a hotel.

The evidence published by AIDS Free World comes from internal UN sources. VICE News was unable to independently confirm the information, but the UN has not contested the accounts. Shortly after the group issued a statement on late Wednesday, the UN confirmed that it had widened the scope of its investigations in the Central African Republic, and said "the exact number and nature of these extremely troubling allegations are still being determined." In a statement, the office of the spokesperson of the Secretary General said that the allegations centered on troops from Burundi and Gabon, as well as French forces deployed as part of a separate "Sangaris" intervention. All three countries, said the UN, had been informed of the allegations.

In December, a panel appointed by Secretary General Ban Ki Moon found that the UN's responses to initial reports of sexual abuse carried out by French soldiers against children should be considered "gross institutional failures." This week, it appears those early cases, which centered around Bangui's airport and began shortly after the French arrived in the Central African Republic in late 2013, were only a drop in the bucket.

According to AIDS Free World, the UN's children agency, UNICEF, this month interviewed 98 girls in just one province, who all said they had been sexually abused by international peacekeepers — a description that appears to encompass both the UN mission itself, as well as the separate French deployment.

Three girls told a MINUSCA human rights officer that in 2014 "they and a fourth girl were tied up and undressed inside a camp by a military commander from the Sangaris force." All four, they said, were "forced to have sex with a dog," then were given the equivalent of around nine dollars.

"The fourth girl later died of an unknown disease," said AIDS Free World in a press release. "One of the survivors said that she was called 'the Sangaris' dog' by people in her community."

The sheer toll of abuse uncovered by UNICEF staff has sent shockwaves through the UN. The incident attributed to French forces is also particularly alarming, as it suggests senior officials were involved in sexual abuse, which may have taken place in a central location with many witnesses.

On Monday, UN spokesperson Stephane Dujarric said that the organization had sent a delegation to Kemo prefecture to investigate alleged incidents dating from 2014 and 2015. The latest incidents, said Dujarric, involved peacekeepers from Burundi and Morocco.

Dujarric said that in just the first three months of this year, MINUSCA has fielded 25 separate allegations. The findings of the UNICEF team suggest the mission may now face more than one hundred open sexual abuse cases — a staggering toll for the UN, which until last year had trumpeted what it called progress in diminishing the prevalence of sexual abuse and exploitation.

In a statement released on Thursday, the UN's human rights chief Zeid Ra'ad al-Hussein called the latest allegations "sickening." Zeid's office was heavily implicated in the panel report from December, which said his office failed to escalate the initial reports of sexual abuse and to notify national authorities.

"We are taking these allegations — some of which are particularly odious — extremely seriously," said Zeid. "It is vital that the victims are protected and receive all necessary care."

The scandal in the Central African Republic has already seen the resignation of Ban's former Special Representative and Head of the MINUSCA, Babacar Gaye, and the expulsion of an entire 800 strong contingent from the Democratic Republic of the Congo. The Congolese forces, which were already implicated in human rights abuses prior to their deployment under MINUSCA, were sent packing by Ban after multiple sexual abuse allegations. The latest allegations appear to involve other troops.