Hong Kong. The Chinese government's move to open an antitrust probe into Google is the latest development in a long and tangled relationship that goes back to the early 2000s.

The investigation was one of a flurry of Chinese retaliatory measures announced Tuesday in response to a 10 percent tariff imposed by US President Donald Trump on imports from China.

Others included tariffs on American liquefied natural gas and other products, and the placing of two other American firms on an unreliable entity list that could bar them from investing in China.

Here is a look at Google's history in China and what the antitrust probe could mean for the company:

What Is Google’s Relationship With China?
Google launched the Chinese-language search engine google.cn in 2006. It was censored to comply with Beijing’s laws, and in 2009, was a major search engine in China with about 36% market share.

In 2010, in response to a cyberattack and an increasing unwillingness to comply with censorship rules, Google said it was no longer willing to block search results and shut down its Chinese search engine, redirecting users to its Hong Kong site instead.

Beijing later blocked Google services under its Great Firewall censorship system, including the email service Gmail, as well as the Chrome browser and search engine, making them inaccessible to users in mainland China.

China typically blocks most Western internet platforms, such as Google, as well as social media platforms including Facebook and Instagram.

Does Google Still Operate in China?
Although Google services are not accessible in China, the company still maintains a presence in the country, primarily focused on sales and engineering for its advertising business. It also has employees working on services including Google Cloud and customer solutions.

Google maintains offices in Beijing, Shanghai and Shenzhen.

Why Is China Investigating Google?
China’s State Administration for Market Regulation said Tuesday it was investigating Google on suspicion of violating antitrust laws.

While regulators did not provide further details, the announcement came minutes after the new US tariffs came into effect.

What Does This Mean for Google?
With few details on what exactly Google is being investigated for, the impact on its operations is unclear, although its immediate status is unlikely to be affected by the probe, which could takes months.

Google did not immediately comment on the investigation.

Some experts believe that the antitrust investigation is likely to center around Google’s Android operating system for smartphones and used as a bargaining chip in the US-China trade war.

John Gong, an antitrust expert at the University of International Business and Economics, said that Chinese smartphone makers have long complained about Google’s market practices.

Virtually all brands apart from Apple and Huawei pay licensing fees to Google to use the Android system on their devices.

“Now, this time, Google is put on the chopping board. But I think it’s still an investigation, right? It hasn’t reached a decision yet,” said Gong, adding, "I think it’s very much negotiable.”

Huawei developed its own HarmonyOS operating system after it was placed on the US entity list — foreign individuals, companies and organizations deemed a national security concern — in 2019, which prevented it from doing business with US firms including Google.

Google has been accused of violating antitrust law in other countries, including those in the European Union, South Korea, Russia, India and Turkey, for allegedly abusing its market dominance.