"Body counts in conflict zones are assumed to be ballpark – hospitals, record offices and mortuaries rarely operate smoothly in war – but this was ten times any other estimate. Iraq Body Count, an antiwar web-based charity that monitors news sources, put the civilian death toll for the same period at just under 50,000, broadly similar to that estimated by the United Nations Development Agency.

The implication of the Lancet study, which involved Iraqi doctors knocking on doors and asking residents about recent deaths in the household, was that Iraqis were being killed on an horrific scale. The controversy has deepened rather than evaporated. Several academics have tried to find out how the Lancet study was conducted; none regards their queries as having been addressed satisfactorily. Researchers contacted by The Times talk of unreturned e-mails or phone calls, or of being sent information that raises fresh doubts.

Iraq Body Count says there is "considerable cause for scepticism" and has complained that its figures had been misleadingly cited in the The Lancet as supporting evidence.

One critic is Professor Michael Spagat, an economist from Royal Holloway College, University of London. He and colleagues at Oxford University point to the possibility of "main street bias" – that people living near major thoroughfares are more at risk from car bombs and other urban menaces. Thus, the figures arrived at were likely to exceed the true number. The Lancet study authors initially told The Times that "there was no main street bias" and later amended their reply to "no evidence of a main street bias".

Professor Spagat says the Lancet paper contains misrepresentations of mortality figures suggested by other organisations, an inaccurate graph, the use of the word "casualties" to mean deaths rather than deaths plus injuries, and the perplexing finding that child deaths have fallen. Using the "three-to-one rule" – the idea that for every death, there are three injuries – there should be close to two million Iraqis seeking hospital treatment, which does not tally with hospital reports.

"The authors ignore contrary evidence, cherry-pick and manipulate supporting evidence and evade inconvenient questions," contends Professor Spagat, who believes the paper was poorly reviewed. "They published a sampling methodology that can overestimate deaths by a wide margin but respond to criticism by claiming that they did not actually follow the procedures that they stated." The paper had "no scientific standing". Did he rule out the possibility of fraud? "No."