The International Press Institute (IPI) today called on the U.S. Justice Department to bring to a close its criminal investigation into Wikileaks over the website’s role in the publication of leaked Defense and State Department documents in 2010.

Authorities have acknowledged that a criminal investigation targeting Wikileaks and its founder, Julian Assange, remains ongoing four years after the documents were published and nearly one year after the soldier who leaked the documents was convicted for doing so.

“The continuation of this investigation – viewed in light of the Obama administration’s prosecution of at least seven American whistleblowers under the Espionage Act, a pattern of conduct many have labelled a ‘war on whistleblowers’ – has an extremely harmful effect on the newsgathering process, particularly the willingness of sources to speak out about abuses and the ability of journalists to interact with those sources,” IPI Executive Director Alison Bethel McKenzie said.

“Criminal prosecution of WikiLeaks or Assange potentially chills not only the fundamental press freedom rights of journalists and their sources, but the right of all Americans to share and receive information – a fundamental prerequisite for democracy. We urge the U.S. government to drop any criminal investigation into activities that assisted whistleblowers in exposing wrongdoing, facilitated government transparency or advanced citizens’ right to receive information in the public interest.”

Supporters of Assange are expected tomorrow to mark the second anniversary of his flight to the Ecuadorian embassy in London to avoid extradition. Assange received political asylum from Ecuador’s government in 2012 and he has remained in the embassy since entering it on June 19, 2012.

Prosecutors in Sweden want to question Assange about sexual assault accusations levelled against him there. Assange rejects the allegations as part of a smear campaign. He has refused to travel to Sweden, maintaining that he fears authorities there will allow him to be extradited to the United States.