The University of East Anglia has breached the Freedom of Information Act by refusing to comply with requests for scientific data, according to the Information Commissioner's Office (ICO).
In a statement, the deputy information commissioner Graham Smith said emails between scientists at the university's Climatic Research Unit (CRU) revealed that “requests made under the Freedom of Information Act were not dealt with as they should have been under the legislation".
The requests, all from climate change sceptics were found to be handled incorrectly by the ICO, but because a six-month limit for prosecutions had elapsed so no action will be taken against the university.
The emails were hacked last November during the Copenhagen summit and placed on the internet to worldwide outrage. There were claims that the scientists had been massaging the figures to make it look more like man was to blame for climate change.
The unit's director Professor Phil Jones resigned during the subsequent inquiry protesting that the CRU had never changed their data.
There will be another independent inquiry into the way the freedom of information requests are handled, headed by former civil servant Sir Muir Russell.
Norfolk police is carrying out an investigation into the hacked emails.