There’s outrage at the United Nations. A U.N. worker was accused of genocide and yet was allowed to stay on the U.N. payroll.
The carnage was horrific. Some 800,000 Tutsis were slaughtered in 1994 by rampaging Hutus in Rwanda. Among those alleged to have done the killing is an employee of the U.N. in Rwanda — a Hutu named Callixte Mbarushimana.
Today, Mbarushimana remains a free man, living in Paris. But there are troubling questions about his conduct in Rwanda a decade ago and the actions of the United Nations.
"They killed on his orders," says Tony Greig, an investigator with the International Criminal Tribunal. "They manned road blocks, they killed people, they got rewarded with cows and beer."
Greig says eyewitnesses directly linked Mbarushimana to more than 30 murders, including killings of fellow U.N. workers.
In witness statements obtained by NBC News, one eyewitness says, "Mbarushimana... shot [a man] in the head as he was standing up." Another claims Mbarushimana "told his [men] to shoot them. The people on the ground were all then shot whilst they were sitting down."
Among those Mbarushimana is accused of killing is a woman and other fellow U.N. employees.
"He was a U.N. employee," says Greig. "He abused his position in the U.N. to kill other U.N. workers."
So what did the United Nations do?
After learning of the allegations in 1999, the U.N. kept Mbarushimana on its payroll. In fact, when he was arrested for genocide, he was working for the U.N. in Kosovo — on a project to stop genocide.
In an exclusive interview with NBC News, Mbarushimana condemns genocide and denies wrongdoing.
"I am innocent of any of the allegations," he says. "No, I have not murdered anybody. I have not participated in the ordering of killing of anybody."
The charges against Mbarushimana eventually were dismissed. Prosecutors say the evidence wasn't strong enough. Investigators dispute that and say prosecutors decided to focus instead on leaders of the genocide and considered Mbarushimana a mid-level figure.
"The decision not to prosecute him was made on the grounds of expediency, not legal grounds, however the U.N. wants to dress it up," says Greig. "He killed many, many people."
This year, investigators were further outraged when a U.N. tribunal ruled that Mbarushimana had been treated unfairly because he was not re-hired after charges were dropped. The tribunal awarded him 13 months of back pay.
Mbarushimana says the accusations have ruined his life. He has been separated from his wife and three children for six years and forced to live as refugee in Paris, where he has no job and has not actually received any compensation to date.
"My family has suffered a lot," he says. "They have suffered because of the lack of financial assets and the education of my children — who are very young — has been interrupted."
U.N. spokesman Fred Eckhard says the U.N. has to abide by the tribunal's ruling, even if awarding back pay to a man accused of genocide and of murdering U.N. employees seems absurd.
"It certainly does [seems absurd]," says Eckhard. "But again, the tribunal considered that this person had not been proven guilty. And, in fact, he hasn't."
Many U.N. officials are furious and embarrassed and some investigators are looking for some way to bring Mbarushimana to trial.
© 2013 NBCNews.com Reprints