The U.N. report said that the 11 other people arrested with Swidan as part of the alleged trafficking ring were unable to identify him and that the conviction was based on his visiting a factory that had once been used to manufacture methamphetamine.
His mother Katherine Swidan told Fox News last year that she wanted President Joe Biden to demand Mark's release.
"I want him to say his name. I want him to be strong and make some demands. Diplomacy is important, I understand that, but this has been going on too long," Katherine Swidan said at the time. "He is not well at all. He's lost 100 pounds."
Harrison Li, the son of Kai Li, told Fox News around a year ago that his father was detained in China while traveling there for a memorial service for his own mother.
"He was not allowed to get off the plane. As soon as he landed at Shanghai Pudong Airport, agents from the Ministry of State Security whisked him away and nobody has been able to see him outside of the prison ever since," Li said.
A website set up to raise awareness for Li said he had been held in China "since September 2016 on politically motivated charges of espionage and stealing state secrets.
"He is currently serving a 10-year prison sentence at Shanghai’s Qingpu Prison," it added.
Leung, who has permanent residency in Hong Kong, was also sentenced on espionage charges in 2023, according to The Wall Street Journal.
He was first detained in April 2021. A friend of Leung told the newspaper that he was involved in charity work supporting low-income elderly people and students in Jiangsu province and has organized tourst between the U.S. and China for musicians.
Fox News’ Kate Sprague, Andrew Mark Miller and Kristine Parks contributed to this report.