UK authorities have said Mr Assange will be arrested if he leaves the Ecuadorean embassy. The founder of the Wikileaks website, Julian Assange, faces rape and sexual assault allegations in Sweden. In June 2012, having lost his appeal to the UK's Supreme Court against extradition to Sweden, he took refuge in the embassy of Ecuador, in London, which granted him asylum.
What are the allegations that Julian Assange faces?
The offences are alleged to have been committed against two women in August 2010. On 20 August 2010, Swedish authorities issued an arrest warrant for Mr Assange on two counts, one of rape and one of molestation.
The warrant was withdrawn a day later, but Swedish prosecutors continued investigations into the molestation allegation.
In September 2010 the rape investigation was re-opened, and in November 2010 a Swedish court approved a request to detain Mr Assange for questioning relating to one count of unlawful coercion, two counts of sexual molestation, and one count of rape. An international arrest warrant was issued relating to those allegations.
Mr Assange denies the allegations and has said they are part of a smear campaign against him.
What is known about the two women?
The two women are not being named as they are alleged victims of sexual offences.
In legal papers they are described only as AA and SW. They met Mr Assange in August 2010 when he was visiting Sweden to give a lecture.
A UK High Court judgement on Mr Assange's extradition cited AA's statement to police, in which she said she first met Mr Assange after she had offered him the use of her flat in Stockholm while she was away. She returned earlier than planned from her trip on 13 August and the pair went out to dinner, before returning to her apartment. It is alleged Mr Assange then committed three offences relating to her - one of unlawful coercion, and two counts of sexual molestation.
Supporters of Mr Assange have said he has not been formally charged with any offence.
SW said in her statement, cited by the UK High Court judgement, that she had attended a lunch with Mr Assange and others on 14 August 2010. He had flirted with her over lunch and they had gone out together, ending up in a cinema. She contacted him on 16 August and invited him to her house in Enkoping. The European Arrest warrant cited by the High Court judgement refers to an offence on 17 August of rape, by "improperly exploiting that she, due to sleep, was in a helpless state".
On 20 August both women went to the police.
It has been previously reported by several media outlets, including the BBC News website, that the two women were ex-Wikileaks volunteers. This was based on a news agency report of a court hearing. However, according to sources, the two women are better described simply as supporters of Wikileaks and its aims.
What is his legal situation in Sweden?
Mr Assange has not been formally charged with any offence. Sweden has requested his extradition so he may be questioned.
In Sweden, charging comes much later in the process of a criminal investigation than it does in many other countries.
In a letter given to Mr Assange's extradition hearing in the UK and quoted in the High Court's subsequent judgement, Swedish Director of Prosecutions Marianne Ny stated: "A formal decision to indict may not be taken at the stage that the criminal process is currently at.
"Julian Assange's case is currently at the stage of 'preliminary investigation'."
His lawyers had asked the UK Supreme Court to block his extradition, arguing that a European arrest warrant issued against him was "invalid and unenforceable".
The key legal question was whether the Swedish prosecutor who issued it had the "judicial authority" to do so under the 2003 Extradition Act - or whether the words gave that power only to a court or a judge.
Despite the lack of formal charges, in its judgement in May 2012, the UK Supreme Court found that the Swedish public prosecutor was a judicial authority capable of issuing the warrant, in the same way as a judge or a court would be.
Why has Ecuador given Mr Assange asylum?
In June 2012 Mr Assange went to the Ecuadorean embassy in London and claimed asylum, which was granted in August.
Ecuador's Foreign Minster Ricardo Patino said Mr Assange's human rights would be at risk if he were extradited and that Ecuador was being loyal to its tradition of protecting those who were vulnerable.
Mr Patino said conditions would be attached to the asylum, such as Mr Assange "not making political statements that could affect our relations with friendly countries".
Before Mr Assange claimed asylum, Ecuador's President Rafael Correa, initially critical of the activities of Wikileaks, had expressed praise for Mr Assange and his work.
Why hasn't he been questioned in the UK?
Swedish prosecutors have interviewed suspects abroad in the past, and in November 2010 Mr Assange's lawyer Mark Stephens said his client had offered to be interviewed at the Swedish embassy in London or via video link.
Since Mr Assange has been in the Ecuadorean embassy in London, Mr Correa and Mr Patino have suggested that Swedish prosecutors could travel to the embassy to meet Mr Assange.
Mr Assange has been living inside the Ecuadorian embassy, in London, since being granted diplomatic asylum.
However, until now Swedish prosecutors have refused to go to London, adamant that Mr Assange should be present in Sweden for the next stage of proceedings.
The prosecutors were criticised in November 2014 by Sweden's Court of Appeal, for failing to explore "alternative avenues" to move the investigation forward.
The crimes Mr Assange is suspected of are subject to statutes of limitation - prosecutors only have until August 2015 to question him about some of the allegations against him, although they have until 2020 to investigate the most serious alleged rape offence.
In March 2015, Swedish prosecutors offered to travel to London to question Mr Assange. Lead prosecutor Marianne Ny announced that a change of strategy was necessary "now that time is of the essence".
Though Ms Ny still believes interviewing him in London could lower the quality of the interview, she said that time limitations made it "necessary to accept such deficiencies to the investigation".
What is likely to happen if and when he is extradited?
Ecuador has shown little sign of being prepared to give Mr Assange up, and the UK has refused to grant him safe passage out of the country, saying he will be arrested if he leaves the embassy for breaching his bail conditions.
If Mr Assange is extradited, he would be detained upon arrival in Sweden - the authorities currently consider him "detained in his absence".
Another hearing would be held within four days to determine whether he should remain in custody.
Once a decision to charge has been made, an indictment is filed with the court. Legal experts say that in the case of a person in pre-trial detention, the trial normally begins within two weeks.
What concerns do Mr Assange and his supporters have over the extradition?
The main concern expressed by Mr Assange and his supporters is that once extradited to Sweden, he would be in danger of being sent to the US, where he fears he could face the death penalty.
Many of Wikileaks' most prominent revelations came from massive releases of classified US military documents on the Afghan and Iraq wars, in July and October 2010. In April 2010, the site released footage showing US soldiers shooting dead 18 civilians from a helicopter in Iraq.
Mr Assange has said he would be in danger of being sent to the US, where he fears he could face the death penalty.
Despite the US not having made an extradition request, US Attorney General Eric Holder has previously said American officials were pursuing a "very serious criminal investigation" into the matter.
Mr Assange has also pointed to the case of Chelsea Manning, an ex American soldier formerly known as Private Bradley Manning, who was sentenced to 35 years in prison in the US for leaking classified material to Wikileaks.
However, legal experts have pointed out several obstacles any extradition and subsequent prosecution in the US would have to overcome.
Correspondents say that Sweden could apply a more stringent test than that used when an extradition is sought from the United Kingdom.
Also, even though the extradition would be according to Swedish law, the UK's approval would be needed.
Mr Assange's supporters have asked Sweden to guarantee that he would not be extradited to the US, which Swedish officials say they cannot legally do.
Swedish Foreign Minister Carl Bildt has however insisted that his country would not extradite a suspect to a country where they would face the death penalty.