Despite revealing last week that it had been the victim of hacking, Rupert Murdoch claims the attacks are continuing, and coming from China.

Last week the New York Times revealed that it had been the victim of a four-month hacking campaign, claiming the attacks originate in China. This revelation was followed by news that both the Wall Street Journal and the Washington Post were also targeted by hackers, with both publications also implicating Chinese attackers.

At the end of the WSJ's own report on the attack, it claimed its security system had been overhauled in recent weeks with the efforts being completed last Thursday, before news of the attack was released.

However this morning Murdoch, whose company News International owns the Wall Street Journal, tweeted: "Chinese still hacking us, or were over weekend." News International has not commented further on the claim.

A weekend editorial in the paper entitled: "Barbarians at the Digital Gate" criticised the Chinese government's denial of the attacks, calling the statement "about as credible as an Andrei Gromyko nyet."

The Chinese authorities have called the allegations "irresponsible" with Chinese Embassy spokesman Geng Shuang saying: " The Chinese government prohibits cyber-attacks and has done what it can to combat such activities in accordance with Chinese laws."

China's Ministry of National Defence called allegations by the New York Times "baseless and unprofessional."

In its editorial at the weekend, the Journal said: "whatever else the Chinese thought they were doing by hacking us, they didn't stop the publication of a single article. Now they have only magnified their embarrassment, as their intrusion was eventually bound to be detected and publicised. Perhaps they will now try to deny us travel visas, harass our journalists or otherwise interfere with our business in China."

Mandiant, the security company brought in by the New York Times, believes cyber-attacks emanating from China are a major problem for the US in general and US media organisations in particular.The company says it is currently monitoring around 20 Chinese groups spying on organisations in the US and around the globe.

The group which it believes carried out the attack on the New York Times is also being tracked by US mobile network AT&T and the FBI, and is according to Mandiant, "very active" having broken into hundreds of other Western organisations, including several American military contractors.