Swedish prosecutors on Thursday ruled out travelling to London to question Julian Assange over alleged sex crimes even though the WikiLeaks founder's lawyer said he had key information relating to the matter.

"There is nothing new. We are still waiting for Mr Assange," Helena Ekstrand, spokeswoman for the prosecutor's office, told AFP when asked about the comments of Assange's lawyer Baltasar Garzon.

Garzon had told the Australian newspaper Sydney Morning Herald that he has key information relating to the rape claims his client was facing and that it would be a "very good option" for the Swedes to travel to London to take a statement.

The Swedish justice's position on the case is not new. The prosecution believes that Assange, who is facing rape and sexual assault allegations from two women from Stockholm, should go to Sweden to give his version of the facts.

A Stockholm district court remanded Assange in custody in absentia in November 2010, and the prosecution has repeatedly stressed that he needs to be in Sweden while the preliminary investigation is ongoing so that he is available to answer any questions that may come up.

"There is a need during questioning with Assange to be able to present him with, and question him about, the evidence that comes forth in the investigation," the prosecution authority explained in a background document on its website.

It added that Assange would be needed "for additional interrogations if necessary."

"If the preliminary investigation finds that there is enough evidence to press charges against Julian Assange, his presence in Sweden is required to carry out a trial," it said.

"The court's custody ruling means that Julian Assange is remanded in custody to ensure this."

Assange, who has been granted political asylum by Quito, is currently holed up in the London embassy of Ecuador to avoid arrest and extradition to Sweden.

He claims if extradited to Sweden, he would be handed over to the United States, where he fears prosecution over WikiLeaks' release of a vast cache of confidential US government files.