"We are calling for an international panel and we are in discussions with WHO (the U.N. World Health Organization) to find the best experts to be in a panel, completely independent... (and) have the best investigation on the source of the outbreak," the Under-Secretary-General for Peacekeeping Operations, Alain Le Roy, said at a U.N. press conference.
There has been speculation that U.N. peacekeepers from Nepal serving in Haiti may have been the source of the epidemic.
"There is no consensus among scientists on this issue," Le Roy said.
None of the Nepalese peacekeepers had either tested positive for, or shown any symptoms of, cholera and repeated testing of water from their camp has not turned up any detectable strain of the disease, the U.N. says.
"We want to make the best effort to get to the bottom of this and find answers that the people of Haiti deserve," U.N. Secretary-General Ban Ki-moon said.
Haiti was in an ongoing recovery operation from a January earthquake that killed more than 200,000 people when cholera broke out in October.