A Swedish prosecutor handling rape allegations against WikiLeaks founder Julian Assange today dismissed suggestions from one of his lawyers that the case might be politically motivated.

And as fresh leaks of US diplomatic cables heaped more embarrassment on Washington, one report suggested that the revelations would force a major reshuffle of their diplomatic, military and intelligence staff.

Swedish prosecutor Marianne Ny, who is handling the rape allegations in Sweden, defended the pursuit of the case in comments to AFP today.

"This investigation has proceeded perfectly normally without any political pressure of any kind," prosecutor Marianne Ny said.

"It is completely independent," she added.

It was Ny who successfully applied for the Interpol Red Notice against Assange, indicating that he was wanted for questioning over the allegations of rape and sexual assault against two women in Sweden.

Earlier today, Assange's British lawyer, Mark Stephens, had expressed concern that the pursuit of Assange had "political motivations", in comments to the BBC.

But Ny said: "I can very clearly say no, there is nothing at all of that nature."

Stephens, in his comments, also warned that WikiLeaks had secret material in reserve, which he likened to a "thermo-nuclear device", to be released if it needed to protect itself.

While it is not clear what this might be, WikiLeaks has already said it plans to release tens of thousands of files exposing abusive practices in US financial institutions.

WikiLeaks has been in the eye of a media and diplomatic storm since it started leaking US diplomatic cables from a collection of some 250,000 it had obtained, embarrassing and infuriating Washington.

Assange, a 39-year-old Australian, who is believed to be in Britain, broke cover on Friday to say in an online chat that he had boosted security after receiving death threats.

WikiLeaks says 831 cables have been posted to its site so far.

Among the latest revelations was one document that said Saudi Arabia was the key source of funding for radical Islamist groups including Al-Qaeda, the Taliban, Lashkar-e-Taiba and Hamas.

Gulf states Qatar and Kuwait were also lax in pursuing locals who donated to the groups, said the cable, an assessment from US Secretary of State Hillary Clinton dated December 30, 2009.