U.N. spokesman Vincenzo Pugliese said the report by French epidemiologist Dr. Renaud Piarroux fails to deliver definitive proof, CNN reported Wednesday.
"We have not dismissed the report but we have not accepted it completely," Pugliese said. "We remain open to investigating this and we will get to the bottom of it."
Piarroux ruled out a number of potential causes when he said the strain of cholera that has killed more than 2,000 in Haiti may have originated with U.N. peacekeepers from Nepal.
He noted that the first cases of cholera were reported just days after a battalion of soldiers arrived from Kathmandu, Nepal, on Oct. 8 and 12.
At the time, Kathmandu was experiencing a cholera outbreak but doctors said none of the arriving soldiers had symptoms of the disease.
Dr. Eric Mintz of the U.S. Centers for Disease Control and Prevention said international researchers are investigating the cause of Haiti's cholera outbreak.