WikiLeaks founder Julian Assange said he would hand himself in to British police Friday in the event of an unfavourable decision from a UN investigation.
"I will accept arrest by British police on Friday if UN rules against me," the 44-year-old Australian said on Twitter.
A UN working group is set to publish a determination on whether Assange, who has been holed up in the Ecuadorian embassy in London since 2012 to avoid extradition to Sweden, is in effect illegally detained there.
Ecuador granted Assange asylum because he was afraid of a possible extradition to the United States, where he is wanted in connection with WikiLeaks' publication of top secret diplomatic cables.
In a BBC report on Thursday, a day before the panel announces its decision, the British broadcaster claimed to know that the panel would rule in favour of Assange.
Assange's legal team said the BBC report came from a deliberate leak by the British government, who already knew the UN panel's decision.
"If it is true, it is not only a great success for Assange," Per E Samuelson, a Swedish attorney representing the WikiLeaks founder, said of the report.
"It means that the prosecutor in Sweden in my firm view has to release Assange and drop the preliminary investigation."
"In that case he has been in detention for a far longer period than a possible sentence, were he to have been found guilty in Sweden," Samuelson adds.
Assange's legal team said it was awaiting official confirmation of the UN panel decision.
"Should the UN announce tomorrow that I have lost my case against the United Kingdom and Sweden I shall exit the embassy at noon on Friday," Assange had announced on Thursday.
"However, should I prevail and the state parties be found to have acted unlawfully, I expect the immediate return of my passport and the termination of further attempts to arrest me."
A spokeswoman for the Swedish Prosecution Authority said they had no comment and were waiting for the UN panel decision on Friday.
Swedish authorities have requested Assange's extradition in connection with several sexual assault allegations. Assange has said he fears further extradition from Sweden on to the US, where he faces other charges.
US authorities are thought to be investigating Assange over the publication of sensitive diplomatic documents, including on the conflict in Afghanistan, by WikiLeaks, the whistleblowing organization he founded.
A rape allegation against Assange is still being investigated, but other cases concerning sexual assaults have been dropped due to the statute of limitations.
The UN Working Group on Arbitrary Detention is a five-member independent and impartial body appointed by the UN. Its current members are from Australia, Benin, Mexico, South Korea and Ukraine.