It began as a rumor that farmers saw waste from a U.N. peacekeeping base flow into a river. Within days of the talk, hundreds downstream had died from cholera.
The mounting circumstantial evidence that U.N. peacekeepers from Nepal brought cholera to Haiti was largely dismissed by U.N. officials. Haitians who asked about it were called political or paranoid. Foreigners were accused of playing "the blame game." The World Health Organization said the question was simply "not a priority."
But this week, after anti-U.N. riots and inquiries from health experts, the top U.N. representative in Haiti said he is taking the allegations very seriously.
"It is very important to know if it came from (the Nepalese base) or not, and someday I hope we will find out," U.N. envoy Edmond Mulet told The Associated Press.
The answer would have implications for U.N. peacekeeping missions around the world, he said.
It would affect the relationship between the U.N. and Haiti: If its peacekeepers misled, it could lose credibility for tasks such as helping oversee next week's election. It could affect the job of U.N. humanitarian workers, who work separately from the peacekeepers.
It would help answer scientific questions: Is the source still out there? How does this cholera strain spread? Does it pose a threat to the region, including the southern United States?
When riots broke out across northern Haiti this week, the U.N. blamed them on politicians trying to disrupt the upcoming vote. But observers say the U.N.'s early stance fanned the flames.
"If the U.N. had said from the beginning, 'We're going to look into this' ... I think that, in fact, would have been the best way in reducing public anger," said Brian Concannon, director of the Institute for Justice & Democracy in Haiti. "The way to contribute to public anger is to lie."
Associated Press writers Michael Stobbe in Atlanta and Edith Lederer at the United Nations contributed to this report.