Apple is facing legal action in China, from a company which said that the Siri voice assistant infringes its patents.

According to Marbridge Daily, Zhizhen Network Technology filed a suit naming Apple’s Chinese subsidiary earlier this year, stating that it contacted the iPhone maker in May 2012 to discuss the issue – but that it did not receive a response.

An unnamed spokesman for the Chinese company was cited as stating that if successful, Zhizhen stands to receive more than the US$60 million Apple recently paid display company Proview Technology to settle a dispute about the use of the iPad name.

Marbridge said that Zhizhen filed its patent with State Intellectual Property Office in August 2004, with approval granted in February 2006. It covers “a type of instant messaging chat bot system.”

Apple recently announced support for Cantonese and Mandarin in the next version of Siri, alongside platform integration with Chinese social networks including Baidu – which was seen as an indication the company is looking to improve its performance in this market.

It has long been suggested that Apple is set to offer an iPhone with support for the TD-SCDMA 3G technology used by China Mobile, the world’s biggest operator by subscriber base.

The iPhone is currently available in China through China Mobile and China Telecom.