The foreign affairs ministry has advised travellers to China to take ’empty’ laptops and mobile phones with them to avoid their data being compromised by the government.

The advice was contained in a letter circulated to 165 businesses and knowledge institutions accompanying prime minister Mark Rutte on a trade mission this week.

The letter says: ‘The Chinese government will want to know everything about you and your business or organisation. You should presume that all computers and phones that enter China are constantly being monitored to obtain this information.’

Sources told the Volkskrant that the cabinet is taking similar precautions for trips to Russia, Iran and Turkey. The last is particularly sensitive because the country is a Nato ally.

The security services have developed a special ‘anti-smart phone’ for government officials on business in these countries, which has extra security features and restricted internet access to prevent hacking. Sensitive documents are not transported digitally but printed out in advance and carried in a briefcase.

Two weeks ago foreign affairs minister Stef Blok warned that the Netherlands risked falling behind in the so-called cyber war between eastern and western nations in a report that named Russia and China as the biggest threats. He said the country ‘faced wide-ranging forms of digital attacks aimed at political and economic espionage and cybercrime.’