On 14 February (London time), Assange tweeted: "Rumours of my death have been greatly exaggerated (in a curious plot)", a paraphrasing of a quote often attributed to American author Mark Twain.
In his Twitter bio, Assange describes himself as a "publisher" and "refugee" who is "picking the lock to the chain that enslaves mankind - ignorance."
WikiLeaks has since tweeted that the @julianassange handle is genuine.
Despite Assange's post, rumours of his death still circulate, with many people online maintaining that anyone could be posting to the account.
Rumours of Assange's death — although sporadically appearing for years — reached a new height when his Internet connection was cut off in October last year by the Ecuadorian embassy, where he has been living since August 2012.
This occurred shortly after WikiLeak’s release of the hacked emails of Hillary Clinton’s campaign chair John Podesta and other Democratic functionaries in October.
At the time, WikiLeaks accused then US Secretary of State John Kerry as having asked Ecuador to cut his access to the Internet, a claim that the State Department denied.