Belmarsh prison Julian Assange Wikileaks
© AFP / Daniel Leal-Olivas Reuters / Peter Nicholls
HMP Belmarsh, London
WikiLeaks co-founder Julian Assange has been visited in prison by the UN's Special Rapporteur as part of an investigation into the Australian journalist's claims that his privacy has been infringed.

Joe Cannataci, the UN's official on the 'right to privacy,' told reporters outside Belmarsh prison in London on Thursday that he is conducting an inquiry into whether Assange's human rights have been breached under international law.

"What we are investigating at this moment of time is whether there's a breach of Article 12 of the Universal Declaration of Human Rights and the Article 17 of the International Government of Civil and Political Rights."

Cannataci explained that Assange's case was "important," because it involves a special set of circumstances, whereby the person in question, who was "not formally under detention yet was subjected to surveillance."

The UN Special Rapporteur added that the investigation will try to establish whether actions taken against the 47 year-old "meet the tests of proportionality and necessity."

Belmarsh is a notorious jail in southeast London used as a holding facility for terrorists and other high-profile prisoners, and has been dubbed 'Britain's Guantanamo Bay.'

Assange is being held in prison after being dragged out of the Ecuadorian Embassy in London on April 11, where he had lived for nearly seven years. He now faces potential extradition to the US, where he faces a charge of conspiracy after publishing documents from whistleblower Chelsea Manning.