US authorities have charged Chinese national Xu Jiaqiang with three counts of economic espionage for allegedly stealing valuable source code from his former employer in the US.
The Department of Justice did not name the employer, but it is widely reported to be software developer IBM.
Mr Xu intended to sell the code for his own profit and for the benefit of the Chinese government, authorities said.
The source code has been described as "a product of decades of work".
The US Attorney's office said Mr Xu had worked as a developer for "a particular US company" from November 2010 to May 2014.
IBM's website, however, has a Xu Jiaqiang still listed as a developer. The company has not commented.
On Tuesday, the DOJ said Mr Xu planned to share the valuable source code with the National Health and Family Planning Commission of the People's Republic of China.
The source code in question was a clustered file system - or one that helps a computer's performance "by coordinating work among multiple servers".
Theft of secrets
China and the US have both flung accusations at each other over state-backed hacking and theft of secrets.
However, China has said in the past that it does not engage in theft of commercial secrets in any form.
Chinese President Xi Jinping said last year that Beijing does not encourage or support such practices in any way.
Mr Xu was first arrested in December for alleged theft of a trade secret from his former employer.
Each of the three counts of espionage carry a maximum sentence of 15 years in prison. The three counts of theft of a trade secret each carry a maximum sentence of 10 years in prison.
Mr Xu's is set to answer the charges in the US on Thursday 16 June.