LONDON, Dec. 7 (UPI) - E-mails purporting to show a coverup by British climate change scientists were hacked in a sophisticated operation originating in Russia, sources say. Citing an unnamed senior member of the U.N.'s Inter-governmental Panel on Climate Change, the British newspaper reported Monday that efforts to access e-mails written by scientists of the Climatic Research Unit at the University of East Anglia were a highly sophisticated, politically motivated operation. The newspaper quoted other unnamed sources saying evidence points to the Russian secret services as the hacker, noting that the purloined e-mails were originally posted on a server in the Siberian city of Tomsk by an Internet security business called Tomcity. Climate change skeptics have seized on the e-mails as evidence that Phil Jones, the East Anglia unit's head, colluded with colleagues to hide unhelpful research that buttressed the skeptics' views. Jones has denied the claims. Rajendra Pachauri, chairman of the U.N. panel, told the BBC on Friday the claims were serious and he wanted them investigated. We will certainly go into the whole lot and then we will take a position on it, Pachauri said.