Julian Assange has denied the rape and molestation charges, saying it is a smear campaign against his website [EPA]

Sweden's criminal police have issued an international arrest warrant for Julian Assange, the founder of whistleblowing website WikiLeaks, who is wanted on suspicion of rape, sexual molestation and unlawful coercion.

Swedish police said on Saturday that the order went out late on Friday through Interpol and the Schengen Information System, a massive security database for Europe's border-free zone.

"The prosecutor had already decided to issue an international arrest warrant," Tommy Kangasvieri of the Swedish National Criminal Police told AFP. "We made sure that all the police forces in the world would see it."

Interpol, based in Lyon in eastern France, said it had received an arrest warrant for the extradition of Assange, an Australian national. He is currently believed to be in Britain.

The warrant comes nearly a month after WikiLeaks published an unprecedented 400,000 classified US documents on the Iraq war detailing torture and civilian deaths blamed on US and Iraqi forces. The website also posted 77,000 secret US files on the Afghan conflict in July.

A Stockholm district court on Thursday ordered an arrest warrant for Assange, 39, for questioning on "probable cause of suspected rape, sexual molestation and unlawful coercion" in Sweden in August.

The court order allowed prosecutor Marianne Ny, who had requested Assange's detention, to prepare an international arrest warrant.

A warrant was first issued for his arrest on August 20 by another prosecutor, but was later withdrawn.

Appeal filed

Ny reopened the rape investigation against Assange on September 1, but did not request his detention and allowed him to leave Sweden.

Earlier on Friday Bjoern Hurtig, Assange's Swedish lawyer, filed an appeal against the arrest warrant court order, but the challenge did not suspend the Swedish order or delay the international warrant.

His lawyer in Britain, Mark Stephens, said the hearing on the warrant was due on Monday, adding that he was "surprised" the Swedish authorities had filed it.

"I am extremely surprised [that the warrant was issued] given that there is an appeal listed for Monday. It seems to me a comprehensive waste of time and smacks of desperation," Stephens told AFP.

He said Assange had offered to be questioned by Ny "at a Swedish embassy in London, at a police station or by videolink" but she had refused, adding that the offer "is still on the table".

Stephens said that, to his knowledge, the international arrest warrant had not yet been received by Assange's lawyers in Sweden or by authorities in relevant countries.

Assange has been accused of raping one woman in Sweden and sexually molesting another.

The founder of WikiLeaks has strongly denied the charges and hinted that they could be part of a "smear campaign" against his whistleblower website for releasing classified war documents.