THE head of the peak United Nations scientific body says he has not begun an investigation into the allegations of a scientific cover-up based on emails hacked from the University of East Anglia's Climate Research Unit.

Speaking to an overflowing audience of scientists and media at the UN climate conference in Copenhagen, Rajendra Pachauri said the main issue was to find out who was behind the theft. ''One can only surmise that those who carried this out have obviously done it with very clear intention to influence the process in Copenhagen,'' he said.

Dr Pachauri, flanked by the senior members of the Intergovernmental Panel on Climate Change, defended the integrity of the scientific findings on climate change, backed the scientists under attack at East Anglia and warned the IPCC's next report was likely to show grimmer news.

Last week he told the BBC the UN's science body would ''look into'' the matter of the stolen emails.

But he told reporters in Copenhagen he had meant the IPCC would examine the affair to see whether the organisation needed to learn any lessons from it.