BEIRUT -- A new United Nations-sponsored report that estimates more than 60,000 people have died in Syria’s political violence has touched off a new dispute that underscores how little is truly known about the toll from a civil war just weeks from beginning its third year.

One Syrian activist who provided some of the numbers for the study says he believes the new numbers are inflated, while another says he believes they underrepresent the dead.

“They are being used as propaganda,” said Rami Abdel Rahman, the head of the London-based Syrian Observatory for Human Rights, who believes the new numbers overstate the number of dead. “The U.N. is not a human rights organization, it is a political one.”

Rahman said he believed the report, made public Wednesday, was being used to pressure countries into working harder to reach a political deal to stop the fighting.

Rahman’s criticism is notable. His organization’s numbers, gathered from informants on the ground in Syria, are the most widely quoted source for information on the daily violence inside Syria. His is also the only organization that attempts to record casualties from all sides of the conflict – rebels, the government and civilians. To date, he’s logged about 46,000 deaths since the uprising against Syrian President Bashar Assad began in March 2011.

Megan Price, a senior statistician for Benetech, the California firm that compiled the report for the U.N. Office of the High Commissioner for Human Rights, said Rahman had shared his concerns with the report’s authors. "We have nothing but the utmost respect for the groups doing this very hard work,” Price said, adding that Rahman’s concerns about the accuracy of some of the data used in the study “are valid."

But she also said she still agreed with the report’s general conclusion that the data used to compile the report, gathered from six organizations and the Syrian government, almost certainly missed a number of deaths that have yet to be counted. “The statistics presented in this report should be considered minimum bounds,” the report said.

“Based on our experience in other countries, and really just thinking about the way that violence occurs, there will inevitably be violence that is not recorded, especially if it leaves behind only the perpetrators or witnesses who don’t feel safe enough to report or they don’t have any reason to,” she said.

That view was endorsed by Radwan Ziadeh, the director of the Syrian Center for Political and Strategic Studies, which is part of another group that tracks casualties, the Syrian Network for Human Rights. The network, which only records deaths of rebel fighters and civilians, has reported the deaths of 42,343 people since March 18, 2011.

The likelihood that many deaths have gone unreported should spur a push for international monitors to document the violence in Syria, said Ziadeh, a member of the Syrian National Council, an opposition exile group that has lobbied hard for international support for the rebels.

“This is why it’s important to have independent fact-finding on the ground,” he said.

Syria’s death toll has long been a hotly debated topic. The United Nations stopped publishing a death toll nearly a year ago after officials realized that they could not independently document the killings and that most of the groups purporting to have information were sympathetic to the rebels and did not delineate between civilian deaths and those of rebel combatants. For its part, the Syrian government provided statistics primarily for its supporters and police and soldiers killed in combat with the rebels. The government stopped publicizing those casualties late last spring as it became clear rebels were taking an ever greater toll on government forces.