Xu was arrested by Belgian police in April 2018 and was eventually extradited to the US. Following his extradition, he was indicted by a federal grand jury for conspiring to commit acts of economic espionage against GE Aviation, a subsidiary of General Electric, which is headquartered in the US state of Ohio. Throughout the trial, which began last week at a District Court in the city of Cincinnati, prosecutors have been making the case that Xu’s espionage activities were part of a broader plan by the MSS to spy on aviation manufacturers around the world. The alleged espionage campaign has been taking place since at least 2013, say the prosecutors.

According to the prosecutors, the purpose of the MSS’ espionage campaign is to reverse-engineer GE Aviation’s advanced gas turbine engine, which, according to one witness who testified at the trial, Beijing has been trying to steal for many years. Among other activities, Xu is accused of having tried to pay off employees of aviation contractors, in return for access to proprietary blueprints of engines and other components. In other cases, computer viruses were used in efforts to compromise secrets. In one alleged example, a project manager with French aviation manufacturer Safran testified this week that his laptop computer was infected with a malware during a 2014 business trip to China.

The trial is expected to last until the middle of November.