image copyrightGetty Imagesimage captionDidi is one of China's largest ride-hailing apps
The ride-hailing app Didi has been ordered off China's app stores, just days after the Chinese tech giant launched its shares in New York.
China's cyberspace regulator said Didi had violated laws on collecting users' personal data and ordered its removal.
The firm said the app would continue to operate, but said it had stopped registering new users.
China has recently moved to tighten up governance of the country's large tech firms.
Didi Chuxing, a platform similar to Uber or Lyft, arranges more than 20 million rides in China every day, on average.
Founded in 2012, it is particularly popular in China's crowded cities. But it has expanded beyond China into 15 other markets.
Last week it raised $4.4bn through an initial public offering in New York, making it the largest share launch since Chinese online retailer Alibaba's in 2014.
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Just a day after shares began trading in New York, the Cyberspace Administration of China (CAC) announced it was investigating the firm to protect "national security and the public interest", prompting the shares to drop 5.3%.
Didi gathers vast amounts of real-time mobility data every day. It uses some of the data for autonomous driving technologies and traffic analysis.
The CAC said: "After checks and verification, the Didi Chuxing app was found to be in serious violation of regulations in its collection and use of personal information."
This investigation follows regulatory crackdowns on other tech firms, from Alibaba to food delivery service Meituan.