WikiLeaks founder Julian Assange was being questioned by prosecutors on Monday at the Ecuadoran embassy in London in the latest twist in the long-running legal battle over a rape allegation against him.
Swedish prosecutor Ingrid Isgren, who will be present while Assange is questioned by an Ecuadoran prosecutor, entered the embassy building shortly before 1000 GMT, an AFP photographer said.
Assange's lawyer Per Samuelsson has said the questioning, which has been delayed in the past because of diplomatic disagreements between Ecuador and Sweden, could last several days.
"I am very hopeful... Objectively, there is no doubt that everything happened as Assange said it did," Samuelsson told Sweden's TT news agency.
"Free Assange" and "You Won't Stop Wikileaks" read banners held up by a small group of protesters outside the embassy as the officials arrived.
"Freedom Loving People of the World Say Thank You Ecuador!" read another banner hung under the balcony from which Assange has sometimes addressed supporters.
A Swedish police inspector will also attend the questioning and investigators plan to take a DNA sample from Assange, subject to his agreement.
The creator of the secret-spilling website has been holed up in the red-brick building behind Harrods luxury department store for more than four years.
The 45-year-old Australian sought refuge in the embassy in June 2012 after Swedish prosecutors issued a European arrest warrant against him, over allegations of rape and sexual assault filed by two women who met Assange during a 2010 trip to Sweden.
He denied the claims, saying they were politically motivated, and insisting his sexual encounters with the two women were consensual.
He has refused to travel to Sweden for questioning, fearing he would be extradited to the United States over WikiLeaks' release of 500,000 secret military files on the wars in Afghanistan and Iraq.
Swedish prosecutors dropped the sexual assault probe last year after the five-year statute of limitations expired.
But they still want to question him about the 2010 rape allegation, which carries a 10-year statute of limitations.
It was the first time Assange has been interviewed over the matter since initial questioning by Swedish police at the time of the allegation.
Assange, speaking through his lawyer, has said he welcomes the "chance to clear his name" and hopes the investigation will subsequently close.
In May, a Swedish court reaffirmed the arrest order, rejecting the finding of a UN working group that his confinement in the Ecuadoran embassy amounted to arbitrary detention.
- Petition for Trump 'pardon' -
In the days since the US election, supporters have launched a petition calling on President-elect Donald Trump to pardon Assange by "absolving him of any crimes alleged against him" -- an apparent reference to the military leaks.
The petition on the change.org website, which has gathered more than 17,700 signatures, hails Assange as a "hero" for exposing the "corruption of those who presume to rule us".
Assange's lawyer said he had made "repeated requests" for an interview with police to address the rape claim, though Ecuadoran prosecutors say a hearing scheduled for October was postponed at the Australian's request.
"Julian Assange has always wanted to tell his version to the Swedish police. He wants a chance to clear his name," Samuelsson told AFP.
The legal grilling comes after WikiLeaks returned to the spotlight with the leak of tens of thousands of emails from the US Democratic Party and presidential candidate Hillary Clinton's campaign in the final weeks of the race for the White House.
Assange defended the publication, denying links with Russia and claims that his website was trying to influence the US vote which saw Trump, a republican, elected.
Tensions with his Ecuadoran hosts have been growing, with the leaks prompting the embassy to cut Assange's internet access, citing respect for "non-intervention" in the affairs of other states.