Google boss Eric Schmidt has called Chinese hackers a "menace" who are using cyber-crime to strengthen their country's political and economic influence.

In extracts from his forthcoming book The New Digital Age, the executive chairman of the search engine giant claims China is: "the world's most active and enthusiastic filterer of information", according to a report in the Wall Street Journal.

For years China has been accused of using cyber espionage to steal commercially valuable information, intimidate opponents, and monitor media coverage of its affairs.

Last week a range of high-profile media outlets including the New York Times and the Wall Street Journal accused the Chinese of hacking into their computer systems.

The Chinese government has denied all allegations of involvement in hacking.

Schmidt, whose book - co-authored with Jared Cohen - is released in April, goes on to say that: "The disparity between American and Chinese firms and their tactics will put both the government and the companies of the United States at a distinct disadvantage."

This, it says, is because Washington "will not take the same path of digital corporate espionage, as its laws are much stricter (and better enforced) and because illicit competition violates the American sense of fair play".

In the book, he explores alleged links between the Chinese government and telecoms company Huawei, and argues that western companies will benefit if they use technology from trusted sources. Huawei has long denied any such links.

"Where Huawei gains market share, the influence and reach of China grow as well," says Schmidt.

However, the authors acknowledge that the US is a far from innocent party in the cyber space battle for hegemony, and describes how the US and Israel created the Stuxnet virus that caused digital chaos worldwide originally to disrupt Iran's nuclear programme.

They go on to argue that western governments will come to work more closely with companies in order to secure their interests, as the Chinese do.

"There will come a time when their commercial and national interests align and contrast with China - say, over the abuse of their products by an authoritarian state - and they [technology companies] will coordinate their efforts with their governments on both diplomatic and technical levels," claim the authors.

In the long run, though, despite the profit China is gaining from the internet, they warn that the prevalence of new technology there will undermine the authoritarian regime.

"This mix of active citizens armed with technological devices and tight government control is exceptionally volatile," they write, warning this could lead to "widespread instability".

In the longer run, China will see "some kind of revolution in the coming decades," they write.