WikiLeaks faced a fresh threat to its survival on Saturday as the online payment service PayPal cut off the account used for donations to the whistle-blowing website.

WikiLeaks is already fighting to stay on the Internet. It switched its domain to Switzerland because its original web address was shut down by a US provider, as it continues to release thousands of classified US diplomatic cables.

At the same time Sweden has issued an amended international arrest warrant for WikiLeaks' founder Julian Assange, who is believed to be in Britain, and The Times newspaper reported he could be arrested next week.

However, other reports said police were unlikely to move to detain the 39-year-old Australian for at least 10 days.

Assange's London-based lawyer Mark Stephens told AFP he did not know whether authorities in Britain had yet received the warrant, which was issued in relation to allegations of rape and sexual molestation in Sweden.

However, Stephens confirmed that any potential arrest of his client would take place by arrangement.

He added: "The last warrant took 10 days to come through, we know that it was incompetently filled out, so another one was sent on Friday.

"So I expect another 10 days, unless of course they are going to treat Julian Assange differently than anyone else."

In a new blow to the website, the US-based PayPal, which is owned by auctions group eBay, announced it would stop taking donations for WikiLeaks thus cutting off a key source of its income.

"PayPal has permanently restricted the account used by WikiLeaks due to a violation of the PayPal acceptable use policy, which states that our payment service cannot be used for any activities that encourage, promote, facilitate or instruct others to engage in illegal activity," it said in a statement.

WikiLeaks blamed "US government pressure" for the PayPal ban, in a message on its Twitter feed.

The latest leaked cables published Saturday by the website of British newspaper The Guardian said the hacking of Google that forced the search engine to pull out of mainland China was orchestrated by a senior member of the communist politburo.

The leading politician became hostile to Google after he entered his own name and found articles criticising him, according to the cables from officials in the US embassy in Beijing.

Meanwhile, Afghan President Hamid Karzai -- one target of the sometimes brutally frank US diplomats' assessments in the cables -- threw doubt on their credibility.

Karzai said at least one of the incidents described in a cable which portrayed him as corrupt and weak could not have happened as described and dismissed others as attempts by US officials to discredit him and his government.

US Secretary of State Hillary Clinton said Saturday she had contacted dozens of foreign leaders to smooth over any frictions caused by the releases and will continue to do so for "the next weeks".

"I haven't seen everybody in the world, and apparently there are 252,000 of these things (leaks) out there in cyberspace somewhere," she said, noting that all of them had not yet been published.

The release marked the third major publication of secret US files by WikiLeaks this year, after the site enraged Washington by publishing tens of thousands of US military files from the Afghanistan and Iraq conflicts.

WikiLeaks was forced to turn to Switzerland for a new domain name after its original wikileaks.org address was shut down by an American provider, while Paris tried to ban French servers from hosting it.

The Swiss domain -- www.wikileaks.ch -- was up and running again on Saturday after migrating to new servers, the group which owns the name said.

Assange broke cover on Friday to say in an online chat that he had increased security after receiving death threats.

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