By Alexandra Valencia and Avril Ormsby
QUITO/LONDON, June 19 (Reuters) - WikiLeaks' founder Julian Assange is seeking asylum in Ecuador after arriving at the South American nation's embassy in London, Ecuador's foreign minister said on Tuesday, a move that may help the self-styled anti-secrecy crusader avoid extradition to Sweden.
The 40-year-old Australian hacker famous for leaking hundreds of thousands of U.S. diplomatic cables has been fighting to avoid being sent to Sweden where he is wanted for questioning over sex crimes.
The situation threatens to inflame tensions between the government of Rafael Correa, Ecuador's leftist and ardently anti-Washington president, and U.S. authorities who accuse Assange of damaging its foreign relations and blowing the cover of diplomatic sources.
"Ecuador is studying and analyzing the request," Foreign Minister Ricardo Patino told reporters in Quito. He added that any decision would be made with "respect for norms and principles of international law."
The Andean nation in 2010 invited Assange to seek residency there but quickly backed off the idea, accusing him of breaking U.S. laws.
Since his detention, Assange has mostly been living under strict bail conditions at the country mansion of a wealthy supporter in eastern England. His associates say that amounts to 540 days under house arrest without charge.
It was not clear how he had arrived at the Ecuadorean embassy in the affluent Knightsbridge area of London.
"While the department assesses Mr. Assange's application, Mr. Assange will remain at the embassy, under the protection of the Ecuadorian Government," the embassy said on its website.
"The decision to consider Mr. Assange's application for protective asylum should in no way be interpreted as the Government of Ecuador interfering in the judicial processes of either the United Kingdom or Sweden."
The Swedish Prosecution Authority said it had no information other than what had appeared in the media.
According to Patino, Assange fears extradition "to a country where espionage and treason are punished with the death penalty." He appeared to be referring to the United States, because Sweden does not have the death penalty.
in 2010, WikiLeaks began releasing secret video footage and thousands of U.S. diplomatic cables, many of them about Iraq and Afghanistan, in the largest leak of classified documents in U.S. history.
Britain's Supreme Court last week said he could be extradited to Sweden in two weeks' time, rejecting his argument that a European arrest warrant issued by Swedish prosecutors for his extradition was invalid..
His only legal recourse in Britain is a possible appeal to the European Court of Human Rights.
Assange, who has not been charged with any offense in Sweden and denies any wrongdoing, has argued that the case is politically motivated because the release of documents on his website has angered the United States.
Swedish prosecutors want to question Assange over allegations of rape and sexual assault made by two female former WikiLeaks volunteers. (Additional reporting by Patrick Lannin in Stockholm; writing by Brian Ellsworth and Daniel Wallis; editing by Mohammad Zargham)