The US Justice Department moved on Thursday to drop all charges against a Chinese researcher arrested last year over visa fraud in its "China Initiative" that aims to prevent the transfer of US technology.
Tang Juan, a visiting researcher at the University of California Davis school of medicine, whose jury trial was set to start on Monday, was arrested in July last year for allegedly concealing her military affiliation.
In a filing with the US District Court for the Eastern District of California, prosecutors said they were moving to dismiss the indictment and vacate the trial, but gave no reasons.
The step comes after the defense called on Monday for the case to be dismissed, based on recently disclosed evidence of a report by FBI analysts that questioned if the visa application question on "military service" was clear enough for Chinese medical scientists at military universities and hospitals.
At least five Chinese researchers were arrested last year over the issue and two are still in jail.
Civil liberties groups, such as the American Civil Liberties Union and the Asian Law Caucus, have voiced concern about the cases, saying they reflect anti-China bias.
Defense lawyers say their clients' real crime is running afoul of US-China politics.
The justice department started the China Initiative three years ago under Republican former President Donald Trump to counter China's national security threats.
The move also comes as US Deputy Secretary of State Wendy Sherman is set to visit China.
Sherman, State's second-ranked official, will meet State Councillor and Foreign Minister Wang Yi and other officials.
The visit could help set the stage for further exchanges and a potential meeting between President Joe Biden and Chinese leader Xi Jinping later this year.
Before Tang's arrest, she sought refuge in China's consulate in San Francisco, following an FBI interrogation with her mother and daughter.
The judge in the case later ordered the FBI interview to be dropped as Tang had not been read her Miranda rights, warning against self-incrimination.
The judge in the case of Song Chen, another Chinese researcher and visiting scholar at Stanford University, had ordered FBI interrogations dropped for the same reason.
Late on Thursday, the government appealed to the Ninth Circuit court against the ruling in Chen's case, a court filing showed.