According to the WSJ staff were given the instructions by their superiors in workplace chat groups or meetings.

The move is the latest step in Beijing's campaign to cut reliance on foreign technology and enhance cybersecurity. It is also concerned about a flow of sensitive information outside of China's borders.

Apple dominates the high-end smartphone market in the country and counts China as one of its biggest markets, relying on it for about 19 per cent of its overall revenue.

It wasn't clear how widely the orders were being distributed, but similar messages were communicated to employees at some central government regulators.

Beijing has for years restricted government officials at some agencies from using iPhones for work, but the order has now been widened, the people said. The latest order also signals an intensified effort by Beijing to ensure its rules are strictly enforced.