France has become the fourth country to speak out against hackers in China following an attack on French government systems.

Francis Delon, France's secretary general for national defence, claimed that the country's systems had been compromised and that the evidence pointed to China.

"We have proof that there was involvement with China," he said. "But that is not to say the Chinese government."

America, the UK and Germany have similarly complained of security attacks that came from the region.

US officials claimed that the Chinese military successfully hacked computers inside the Pentagon in June.

Meanwhile, German chancellor Angela Merkel also complained that her government's systems had been penetrated by Chinese hackers, raising the subject with Chinese president Hu Jintao.

The UK government was accused last week of covering up the scale of the breach to its systems by a member of the Commons Foreign Affairs Committee.

China has denied all claims that it is behind the hacking attacks.