The material was taken from servers at the University of East Anglia’s Climatic Research Unit – a world-renowned climate change research centre – before it was published on websites run by climate change sceptics.
It has been claimed that the emails show that scientists manipulated data to bolster their argument that global warming is genuine and is being caused by human actions.
One email seized upon by sceptics as supposed evidence of this, refers to a “trick” being employed to massage temperature statistics to “hide the decline”.
The university yesterday confirmed that research data had been stolen and published online and said it had reported the security breach to police.
A spokesman said: “We are aware that information from a server used for research information in one area of the university has been made available on public websites.
“Because of the volume of this information we cannot currently confirm that all this material is genuine.
“This information has been obtained and published without our permission and we took immediate action to remove the server in question from operation. We are undertaking a thorough internal investigation and have involved the police in this inquiry."
The files were apparently first uploaded on to a Russian server and then mirrored across the internet.
An anonymous statement accompanying the emails said: “We feel that climate science is too important to be kept under wraps. We hereby release a random selection of correspondence, code, and documents. Hopefully it will give some insight into the science and the people behind it.”
One of the emails under scrutiny, dated November 1999, reads: "I've just completed Mike's Nature [the science journal] trick of adding in the real temps to each series for the last 20 years (ie, from 1981 onwards) and from 1961 for Keith's to hide the decline."
Scientists who are alleged to be the authors of the emails in question have declined to comment on the matter.