Thousands more 'Climategate' emails from the University of East Anglia have been leaked in another attempt to cast doubt on the validity of climate science.
The 5,000 emails have been posted online just days before the latest round of UN climate talks in Durban.
They all date from 2009 or before, indicating that they formed part of the original archive, stolen in that year. Messages leaked at the time led to investigations worldwide that climate data had been 'massaged' to back up theories about man-made climate
In the end, the scientists concerned were cleared of dishonesty, although they were criticized for failing to share information as a result of freedom of information requests.
"If genuine, (the sheer volume of material makes it impossible to confirm at present that they are all genuine) these emails have the appearance of having been held back after the theft of data and emails in 2009 to be released at a time designed to cause maximum disruption to the imminent international climate talks," says the University of East Anglia in a statement.
"This appears to be a carefully-timed attempt to reignite controversy over the science behind climate change when that science has been vindicated by three separate independent inquiries and number of studies – including, most recently, the Berkeley Earth Surface Temperature group."
Like the original batch of emails, the new set appears to imply that University researchers were economical with the truth.
"One way to cover yourself... would be to delete all emails at the end of the process. Hard to do, as not everybody will remember to do it," reads one purporting to have been sent by professor Phil Jones of the University's Climatic Research Unit.
But while they raise the same concerns as the original leaked emails - that information was not adequately shared - they appear to add little, if any, new information.
"As in 2009, extracts from emails have been taken completely out of context," says the university.
"Following the previous release of emails scientists highlighted by the controversy have been vindicated by independent review, and claims that their science cannot or should not be trusted are entirely unsupported."