"CHINESE spies have hacked into German government department computer systems, media reports say.
The reports emerged as German Chancellor Angela Merkel arrived in China.
The Chinese Foreign Ministry reacted by saying China prohibited attacks on computer networks.
"The Chinese Government has always opposed and prohibited any criminal activity that breaks down computer networks, including hacker attacks," Foreign Ministry spokeswoman Jiang Yu said.
"China has clear rules and regulations on this."
German weekly Der Spiegel reported espionage programs had been detected in computer systems at Ms Merkel's office, the Foreign Ministry and other government agencies in Berlin.
Investigations showed the programs could be traced back to People's Liberation Army hackers, it said.
"Hacking is an international issue and China itself is often attacked," Ms Jiang said. "