It might not be the best idea to annoy the government of a country where you're trying to develop new business, but Apple Inc. (NASDAQ:AAPL) is doing just that. The Cupertino, Calif.-based company is suing a Chinese government agency along with a Chinese company over the patent for “Siri.”

Apple officially launched the case against the State Intellectual Property Office and software developer Shanghai Zhizhen Network Technology on Monday, and the Beijing Number One Intermediate People’s Court is set to hear the case on Thursday, according to Xinhua.

The dispute arose when Zhizhen accused Apple of copying its “Xiao I Robot,” patented in 2004, in Apple’s development of Siri, the intelligent personal assistant app that uses a natural-language user interface. Zhizhen claimed at the time that its product works in a similar way to Apple’s Siri, which debuted with the release of the iPhone 4s in 2011. The case was heard by a Shanghai court in July, but there was no ruling.

Apple has in turn asked the State Intellectual Property Office to declare Zhizhen’s voice-recognition patent invalid. When the request was declined, Apple followed up with the current legal action, according to Xinhua.

The dispute comes at a time when Apple is making major headway in China, the world’s largest smartphone market. In December, Apple CEO Tim Cook inked a partnership with China Mobile (NYSE:CHL), mainland China’s biggest mobile carrier, a deal that was years in the making.

“I think there are lots more things our companies can do together in the future,” Cook said in January.

Even before China Mobile began selling iPhones in January, Apple’s fortunes in China were looking up. In the last quarter of 2013, Apple increased its share of the Chinese market to 7 percent, slowly catching up with Korean smartphone maker Samsung Electronics Co. Ltd. (KRX:005930) and domestic companies like Lenovo Group Ltd. (HKG:0992) and Huawei Technologies.