VANCOUVER: Researchers claimed that the common estimate of 5.4 million deaths due to war in the Democratic Republic of the Congo is vastly inflated.

The 2010 Human Security Report, released Wednesday at the United Nations in New York, challenged the research used to arrive at the figure, saying "estimates of the Democratic Republic of the Congo's war death toll are at least twice as high as they should be."

The shocking death-toll estimate has been used worldwide to bolster political support for a massive UN peacekeeping mission and humanitarian aid in the heart of Africa.

The estimate of 5.4 million war deaths -- most from indirect causes including starvation and disease since war began in 1998 -- was calculated from a series of five surveys by the International Rescue Committee and, in two of the surveys, by the Burnet Institute of Australia.

But Andrew Mack, ex-strategic planning director to former UN secretary-general Kofi Annan and now director of the Human Security Report Project at Simon Fraser University in Vancouver, criticized the survey methods.

For example, he told AFP, the IRC assumed the DRCongo's mortality rate before the war was the same as the average rate in sub-Saharan Africa -- but in fact conditions in the DRCongo were far worse than the regional average even before the war.

By substituting a "more appropriate" pre-war mortality rate in the IRC data, Mack estimated 900,000 people died between 2001 and 2007 who would have lived had there been no war -- far fewer than the IRC estimate of 2.83 million, which Mack suggested included deaths that would have occurred anyway.

Mack did not give his own estimate for a death toll.

But he noted the first two of the IRC surveys were not done in a randomly-selected area on a representative population, as is standard in statistical research.

The IRC and the Burnet Institute responded with a joint email to AFP that they "strongly affirm" findings "based on standard and scientifically-grounded methodology (and which) remain the best estimates available of conflict-related mortality in Congo."

The email said researchers previously acknowledged the criticisms raised by the Human Security Report, which "do not invalidate our findings ... our estimates have been supported by numerous other studies."

"We believe this information is valid and that it has been and continues to be of essential value to public health and political decision-makers," said the IRC and Burnet.

The Human Security Report, called The Shrinking Costs of War, said estimates of war death tolls in Iraq, Sudan and now the DR Congo have become controversial and highly-politicized.

Mack told AFP disputes put billions of dollars in humanitarian aid at risk by "discrediting population health surveys as a whole."

"Policy makers need to have hard data... anything that questions the credibility of these surveys is a bad thing."

Mack called on the United Nations to mandate a national population health survey to provide evidence in each country where the Security Council launches a new peace-keeping operation.