The University of East Anglia's Climatic Research Unit (CRU) has been under attack since hacked e-mails were leaked online last year, which sceptics claimed showed scientists manipulated data to support a theory of manmade global warming.

However,ADVERTISEMENTa detailed review of 11 scientific papers published over 20 years gave the CRU's research a clean bill of health, judging the scientists had arrived at their conclusions "honestly and sensibly".

The probe, conducted in the past month, found "no evidence of any deliberate scientific malpractice" at the centre.

Lord Oxburgh, a former non-executive chairman of oil giant Shell, who headed the panel conducting the review, said they had uncovered "absolutely no evidence of any impropriety".

He said reviewers found scientists could have used better statistical methods in analysing some data, but it was unlikely to have made much difference to results.

Responding to the findings, the University of East Anglia said the inquiry showed months of attacks on its scientific integrity were "totally unjustified".

And Bob Ward, of the Grantham Research Institute on Climate Change and the Environment at LSE, who was critical of the stance taken by sceptics, called on them to apologise for misleading the public over the e-mails' significance.

Much of the criticism over the e-mails focused on comments by the CRU's head, Professor Phil Jones, including a reference he made to a "trick" to "hide the decline". The comment related to dealing with the divergence in the 1960s between actual temperature records and "proxy" temperatures deduced from tree rings.

After reading the papers, looking at other work and conducting interviews with senior staff at CRU, the reviewers concluded the tree-ring work by the unit had been "carried out with integrity".

Lord Oxburgh said he suspected many of the claims were made by people "who do not like the implications of some of the conclusions CRU had come to".

He claimed that Freedom of Information requests – which CRU received in numbers from sceptics and which the e-mails suggest the scientists tried to block – could be an instrument of harassment.

The review said much of the record-keeping at CRU was not good, as the scientists had not foreseen how high profile their research would become.

Nevertheless, the release of the e-mails, which were easy to misinterpret, had been damaging for the credibility of climate science.

"I hope our report will go some way to remedying that. Whatever was said in the e-mails, the basic science seems to have been done honestly and fairly."

The university's vice-chancellor, Edward Acton, said: "This has been a horrendous experience for Phil Jones personally and a turbulent time for CRU and the university.

"We have had months of vilification against our most precious asset of scientific integrity which, as this report confirms yet again, was totally unjustified."