The director of a U.K research unit has said he is standing down from his post after hundreds of private e-mails were published on the internet when a computer hacker breached the security of the CRU database in November and stole numerous materials that are skeptical about climate change.

Professor Phil Jones, director of the U.K.'s University of East Anglia's Climatic Research Unit said he steps aside while the investigation takes place and it was important that the CRU continues its world leading research with as little interruption and diversion as possible.

The investigation on these leaked emails became public about two weeks ago after they were hacked from a computer server at the University of East Anglia in England.

Many of the e-mail messages, which date back to the mid-1990s, appeared to critics to show unseemly manipulation of scientific data.

Critics say the messages indicate the scientists who wrote them, who believe in human-caused climate change, wanted to hide key data or keep information from being publicly released, to make climate-change skeptics look bad.

The e-mails also caused controversy on Capitol Hill where a congressional hearing on global warming was under way Wednesday.