But Phil Jones, of the University of East Anglia's Climatic Research Unit, defended on Monday his decision not to release the data about temperatures from around the world, saying it was not "standard practice" to do so. "I have obviously written some pretty awful emails," Jones told British lawmakers in response to a question about a message he sent to a sceptic in which he refused to release data saying he believed it would be misused.

The admission from the scientist, who has stood aside as director of the climate centre while investigations take place, came at a parliamentary hearing in UK into the scandal. The research centre came under fire ahead of key climate talks in Copenhagen in December, after more than 1,000 emails and 3,000 other documents were hacked from the university's server and posted online.

Sceptics claimed they showed evidence scientists were manipulating climate data in a bid to exaggerate the case for manmade global warming as world leaders met to try and strike a new accord on climate change. Jones — who has said the fallout from the affair prompted him to consider suicide — had referred in one private email to a "trick" being employed to massage temperature statistics to "hide the decline".

He has since insisted the emails had been taken out of context and labelled allegations that he sought to exaggerate warming evidence as "complete rubbish." Eighty percent of the data used to create a series of average global temperatures showing the world was getting warmer had been released, said the scientist.

Climate expert in email row says hid data to stop misuse