A new study suggests that the deadly cholera outbreak in Haiti was spread by United Nations peacekeepers.

In the strongest argument yet, scientists say a peacekeeping force from Nepal brought the cholera strain that killed thousands.

The disease has killed more than 5,500 people and sickened more than 363,000 others since it was discovered in October, according to the Haitian government.

Cholera is caused by a bacteria that produces severe diarrhea and is contracted by eating or drinking contaminated food or water.

The disease has spread to the neighboring Dominican Republic, where more than 36 deaths have been reported since November.

The report points to bad sanitation at the U.N. base near the town of Mirebalais, which led to the contamination of the Haitian waterways.

"Our findings strongly suggest that contamination of the Artibonite and one of its tributaries downstream from a military camp triggered the epidemic," researchers said in the report.

Their findings are published in the July issue of Emerging Infectious Diseases, a journal of the U.S. Centers for Disease Control and Prevention.

The study also criticizes the U.N. for initially refusing to investigate the outbreak's origin.

The panel's report was ordered by U.N. Secretary-General Ban Ki-moon as anti-U.N. protests spread in Haiti and mounting circumstantial evidence pointed to the troops.