Wikileaks founder Julian Assange has defied a British police order for extradition to Sweden, staying instead in the embassy of Ecuador.

Assange had been served with a letter from British police requesting that he surrender himself to authorities on Friday. He was faced with a "difficult choice" in defying the police order, a lawyer of his said on Friday. He is hoping Ecuador will grant him political asylum.

"He had two very difficult choices. I think he would go to Sweden immediately if he got assurances from the United States that there was not going to be a prosecution," human rights attorney Michael Ratner said Friday.

Such an arrangement, Ratner explained, would have to provide a clear guarantee with no "minced words."

In Sweden, Assange is wanted to answer questions over sexual assault. He insists, however, that he is innocent and that the charges are all part of a politically motivated effort to get him extradited to the United States.

The US has said it has no role in the extradition dispute.

Wikileaks released some 250,000 confidential US diplomatic cables in 2010, infuriating Washington.

Assange's supporters paint him as a whistle-blowing hero, but his critics denounce him as a traitorous anarchist.

His defense lawyer expressed cautious optimism that Ecuador would approve Assange's request for asylum.

"I'm very hopeful about it, I'll put it that way. They have the ability and the president and the country have the guts to stand up to the United States," said Ratner, citing Ecuador's decision to close a US military base in 2008.

tm/slk (AFP, dpa)