U.S. federal prosecutors will not file new charges against Dr. Xi Xiaoxing, a Temple University professor who had been accused of scheming to provide classified U.S. technology to China. Xi’s seized property will also be returned, said Michael A. Schwartz, one of Xi's lawyers, on Monday.

Last May, the U.S. Department of Justice arrested 57-year-old Xi, a naturalized U.S. citizen born in China, and accused him of "sharing sensitive American-made technology with China."

He was charged with wire fraud, allegedly involving in the transfer of technology to entities in China while he worked with a U.S. company developing a thin-film superconducting device containing magnesium diboride in 2002.

But a few months later, independent experts discovered something wrong with the evidence. The technology discussed in Dr. Xi's emails to scientists in China was not sensitive or restricted. Therefore, in September 2015, the U.S. Department of Justice dropped all charges against Dr. Xi.

Xi's other lawyer, Peter Zeidenberg, said it appeared that the government never consulted with experts before taking the case to a grand jury. As a result, prosecutors misconstrued the evidence, according to the New York Times.

Xi was chairman of the university's physics department until his arrest. He currently remains a faculty member.