The live Q&A with Julian Assange was scheduled to start at 1pm, but the URL for the interview redirected to a 404 error page. Other sections of the Guardian website were also affected, including the site's coverage of the latest leak from WikiLeaks involving more than 250,000 diplomatic cables sent by US embassies across the globe.
A tweet from the Guardian's technology team confirmed that the outage was a result of a "huge load" on the site's server because of the Assange Q&A.
At time of writing the site and the interview page had recovered, though the page was slow to load.
Earlier this week Interpol made public a 'Red Notice' or international wanted persons alert for Assange relating to allegations of sexual offences. Amazon also ceased hosting WikiLeaks' servers this week, while its web address host also pulled support from the whistleblowing site.