The FBI is currently investigating the disappearance of Ohio State University (OSU) professor Rongxing Li, 56, who participated in numerous NASA projects before abruptly resigning from his job and disappearing in February of 2014, according to the Daily Mail. The FBI's involvement comes after suspicions arose that Li was sharing defense secrets with the Chinese government; notably, Xi participated in the 2003 Mars Exploration Rover mission, where he had access to information that he was strictly prohibited from sharing with the Chinese.

Li disappeared in February after resigning and told OSU that he had returned to China to aid his sick parents. Li's wife, Jue Tian, was searched by Homeland Security agents before she boarded a plane in March and they found USB drives with restricted U.S. defense information, according to the Business Insider.

Li wrote a Mars 2020 NASA imaging mission proposal in which he stated that he had no ties to China. The proposal give him access to prohibited Department of Defense information, according to The Columbus Dispatch. However, OSU knew that he had ties to Tongji University in Shanghai, which is what prompted an internal investigation into Li.

As of yet, no charges have been placed against Li or his wife, who returned to the U.S in the middle of 2014.