China has ordered public spaces offering wi-fi web access to install costly software to enable police to identify people using the service, state media said Thursday.

The software, which also gives police a list of all websites visited by an online user, costs between 20,000 yuan ($3,100) and 60,000 yuan, the China Business News said.

As a result, many establishments such as bars, restaurants, cafes and bookstores have decided to stop providing wireless Internet to their customers despite its popularity, to avoid paying the money, the report said.

In Beijing, cafe and restaurant owners have been told they face a minimum fine of 5,000 yuan if they continue to offer wireless without installing the software, it said.

"In serious cases," offenders could see their Internet cut off for up to six months, the report said.

Cafe owners in Shanghai and in the eastern city of Hangzhou contacted by the official China Daily newspaper said they had also been notified of the new measure, which other reports have said is being rolled out nationwide.

The software is purportedly designed to supervise "illegal activities," the report said.

"It's a requirement of the public security organs. Why should we pay the fees?" Yang Xiaowen, manager of UBC Coffee in Beijing, told the China Daily.

"For a reason that everyone is aware of, we are temporarily stopping our wi-fi service," announced the Beijing-based Kubrick bookstore, according to the China Business News.

The report also raised questions about ties between police and the software maker Rainsoft, a company founded in 1998 that reportedly collaborates with public security organs in many Chinese provinces.

China -- which has the world's largest online population with 485 million users -- constantly strives to exert its control over the Internet, blocking content it deems politically sensitive as part of a vast censorship system.

In one high-profile case in 2009, it ordered computer makers to add an Internet filter software to all new personal computers sold in the country, saying it would shelter children from pornographic and violent web content.

But it was forced to back down on the plan just ahead of the deadline after an outcry in China and abroad.