The latest criticism of the Intergovernmental Panel for Climate Change headed by India's R K Pachauri comes after the panel admitted its mistake in asserting that Himalayan glaciers could disappear by 2035.

The report also included another claim that rapidly rising costs from events such as floods and hurricanes were linked to climate change.

"We are reassessing the evidence and will publish a report on natural disasters and extreme weather with the latest findings. Despite recent events the IPCC process is still very rigorous and scientific," The Sunday Times quoted Jean-Pascal van Ypersele, vice-chair of the IPCC as saying.

According to the newspaper, the panel based the claims on an unpublished report that had not been subjected to routine scientific scrutiny - and ignored warnings from scientific advisers. The report's author later withdrew the claim because the evidence was too weak.

The link was central to demands at last month's Copenhagen climate summit by African nations for compensation of USD 100 billion from the rich nations blamed for creating the most emissions.

According to the newspaper, the panel knew in 2008 that the link could not be proved but did not alert world leaders. Ed Miliband, the energy and climate change minister, has suggested British and overseas floods - such as those in Bangladesh in 2007 - could be linked to global warming.

US President Barack Obama said last autumn: "More powerful storms and floods threaten every continent."

In another report, The Sunday Telegraph said the scientist whose report originally claimed that Himalayan glaciers could disappear by 2035, has for the past two years been working as a senior employee of The Energy and Resources Institute, (TERI) the Delhi-based company of which Pachauri is director-general.

The new controversy also goes back to the IPCC's 2007 report in which a separate section warned that the world had "suffered rapidly rising costs due to extreme weather-related events since the 1970s".

It said a part of this increase was due to global warming. The academic paper at the centre of the latest questions was written in 2006 by Robert Muir-Wood, head of research at Risk Management Solutions, a London consultancy, who later became a contributing author to the section of the IPCC's 2007 report dealing with climate change impacts.

Muir-Wood wanted to find out if the 8 per cent year-on-year increase in global losses caused by weather-related disasters. He found from 1950 to 2005 there was no increase in the impact of disasters once growth was accounted for. For 1970-2005, however, he found a 2 per cent annual increase which "corresponded with a period of rising global temperatures."