WikiLeaks founder Julian Assange should not be extradited to the United States because it would have a chilling effect on press freedom, a European human rights chief said on Thursday.
Assange, 48, is in prison in London, where an extradition hearing begins next week. The US authorities want to try him on 18 counts including conspiring to hack government computers and violating an espionage law.
Dunja Mijatovic, the Council of Europe's Human Rights Commissioner, said Assange's case raised questions about the protection of people who publish classified information in the public interest, exposing human rights violations.
"The broad and vague nature of the allegations against Julian Assange, and of the offences listed in the indictment, are troubling as many of them concern activities at the core of investigative journalism in Europe and beyond," she said.
"Consequently, allowing Julian Assange's extradition on this basis would have a chilling effect on media freedom, and could ultimately hamper the press in performing its task as purveyor of information and public watchdog in democratic societies."
Mijatovic said she was also concerned about detention conditions in the United States and about the sentence likely to be imposed on Assange. He could spend decades in prison if convicted.
The Council of Europe, which describes itself as the continent's leading human rights organization, has 47 member states including Britain, all of which are signatories to the European Convention on Human Rights.
Assange's WikiLeaks website made global headlines in early 2010 when it published a classified US military video showing a 2007 helicopter attack in Baghdad that killed a dozen people, including two Reuters news staff.
Since then, the website has published a vast amount of secret US diplomatic cables and other confidential documents.
Assange presents himself as a champion of free speech holding a superpower to account, but critics accuse him of irresponsibly putting lives at risk with his unedited information dumps.
After WikiLeaks published leaked emails during the 2016 US presidential campaign that damaged Democratic candidate Hillary Clinton, he was accused of complicity in Russian efforts to meddle in US politics and undermine the West.