A contingent of U.N. peacekeepers is the likely source of a cholera outbreak in Haiti that has killed at least 2,000 people, a French scientist said in a report obtained Tuesday by The Associated Press.

Epidemiologist Renaud Piarroux concluded that the cholera originated in a tributary of Haiti’s Artibonite river, next to a U.N. base outside the town of Mirebalais. He was sent by the French government to assist Haitian health officials in determining the source of the outbreak, a French Foreign Ministry official said Tuesday.

“No other hypothesis could be found to explain the outbreak of a cholera epidemic in this village … not affected by the earthquake earlier this year and located dozens of kilometers from the coast and (tent) camps,” he wrote in a report that has not been publicly released.

The report also calls for a further investigation of the outbreak, improved medical surveillance and sanitation procedures for U.N. peacekeeping troops and better support for Haitian health authorities.

The AP obtained a copy of the report from an official who released it on condition of anonymity. Piarroux confirmed he had authored the report but declined in an e-mail interview to discuss his findings. Copies were sent to U.N. and Haitian officials, the foreign ministry confirmed.

The U.S. Centers for Disease Control and Prevention confirmed in October that the strain of cholera bacteria in Haiti matched one from South Asia, a region that includes Nepal, but said it had no further information about the cause of the outbreak at the time.

Many Haitians have long suspected the Nepalese base was the source of the disease, and anger at the troops sparked a week of riots in which U.N. soldiers were injured and several Haitians were killed.

The report says that the first cases of the disease were from the village of Meille, where the base is located. The first confirmed case, a 20-year-old man from the village, developed symptoms on Oct. 14 and was found by Cuban doctors at a hospital in nearby Mirebalais.

Haitian investigators “indicated that the first patients were obtaining drinking water from a tributary of the Artibonite River flowing just below the (U.N.) base,” he said.

It notes that the rotation of soldiers began arriving days before those first cases from Nepal, where there were cholera outbreaks over the summer.