Chinese technology company Huawei has found itself in a controversy after a former employee was wrongfully detained for more than eight months on extortion charges.

Li Hongyuan, 42, who had worked at Huawei for more than 12 years, was arrested by Shenzhen police on Dec 16 and detained until Aug 23, when Shenzhen prosecutors decided to drop the charges because of "unclear criminal facts and insufficient evidence", according to two documents from the city's Longgang district procuratorate.

Li recently posted the documents in a WeChat group of former Huawei employees to prove his innocence.