China has quickly and angrily rebuffed media reports which suggested that the country was behind the hacking attack on Mitsubishi heavy, Japan’s biggest weapons contractor.

A Chinese foreign ministry spokesman Hong Lei told reporters, "The Chinese government has consistently opposed hacking activities. The law strictly prohibits this."

As in the past, when the country refuted suggestions that it was behind the hack attacks on government servers in South Korea, the spokesman said that China itself is a victim of hacking.

"China is one of the main victims of hacking … criticising China as being the source of the hacking attacks is not only baseless, it is also not beneficial for promoting international co-operation for internet security," said Hong Lei.

Recently, Mitsubishi Heavy Industries Limited disclosed that hackers have stolen data from its database after a hack attack, believed to be the first hack attack on Japan’s defence industry.

Mitsubishi Heavy said that some information, including IP addresses, could have been stolen in the attack, but crucial data remains safe. The company said that it had identified the hack attack on 11 August, which has raised concerns in the Japanese government.

According to the Guardian, under its agreement with the Tokyo government, the company is required to immediately inform authorities of any suspected breach of sensitive or classified information.

Tokyo-based Mitsubishi Heavy produces jet fighters, anti-submarine helicopters, develops civilian aircraft components, and also runs a nuclear fuel manufacturing plant. The company is Japan’s biggest defence contractor and has also been working closely with Boeing, making key components for its jets.