Police investigating the theft of "Climategate" emails from the University of East Anglia have seized computer equipment from the home of a climate-sceptic blogger in West Yorkshire.
Norfolk Constabulary, which is leading the inquiry into the theft of thousands of emails from university computers, said nobody was arrested during Wednesday's raid.
"This is one line of inquiry in an investigation started in 2009," it said. A spokeswoman refused to say whether it was the first time computers had been seized during the two-year investigation.
The first batch of hacked emailswas released on the internet through a server in Russia in December 2009, just before the climate change summit in Copenhagen. A second tranche of about 5,000 emails was released just before the Durban conference, which ended last weekend.
Climate contrarians said the content of the emails demonstrated that there was a conspiracy among climate scientists to spin the evidence in favour of global warming and downgrade any opposition. But three separate investigations in Britain and two in the US have found no evidence of such fraud.
Details of the police raid were released by the blogger, known as "Tallbloke".
He said six police officers had arrived on his doorstep with a search warrant.
"I waved the first three in and bid them head through to the sitting room, where there was less of an [sic] chill near the wood burner. Then they kept coming, being introduced by the lead detective from Norfolk as they trooped in," he wrote.
"I thought I'd been chosen to host the secret policemen's ball or something."
The blogger – whose real name is Roger Tattersall – is a digital content manager at Leeds University. In an email to The Independent yesterday, he denied having anything to do with the hacking of emails from the Climatic Research Unit (CRU).
"I am not the person who took the data and emails from the CRU," he said.
"I just happen to run a science blog which was the recipient of a comment containing a link to the second tranche of 'Climategate' emails.
"The three investigations in Britain were a joke. The Parliamentary Select Committee was told not to investigate the science because the other inquiries would. The Oxburgh inquiry was headed by a man who is part of the inner circle, as revealed in the emails. The Russell Inquiry thought the best person to ask which evidence they should consider was the person being investigated – Professor Phil Jones."
A spokesman for the University of East Anglia said: "We are pleased to hear that the police are continuing actively to pursue the case following the release last month of a second tranche of hacked emails from the Climatic Research Unit.
"We hope this will result in the arrest of those responsible for the theft of the emails and for distorting the debate on the globally important issue of climate change."