U.S. prosecutors charged two men tied to the U.S. Department of Homeland Security (DHS) as part of what federal law enforcement officials have called a “transnational repression scheme” on behalf of the Chinese government to spy on and harass dissidents living in the United States.

The two charged were Craig Miller, who has worked as a DHS deportation officer for 15 years in Minnesota, and Derrick Taylor, a retired DHS law enforcement agent now working as a private investigator in California, the U.S. Department of Justice said on Thursday.

On Wednesday, a grand jury returned an indictment charging the two men and three others with crimes committed while acting as alleged Chinese agents, the department said in a statement.

U.S. Assistant Attorney General for National Security Matthew Olsen delivers remarks on U.S. Department of Justice policy, in Arlington, Virginia, Feb. 23, 2022.

U.S. Assistant Attorney General for National Security Matthew Olsen delivers remarks on U.S. Department of Justice policy, in Arlington, Virginia, Feb. 23, 2022.

“We will defend the rights of people in the United States to engage in free speech and political expression,” said Assistant Attorney General for National Security Matthew Olsen. “These individuals aided agents of a foreign government in seeking to suppress dissenting voices who have taken refuge here.”

Of the three other individuals, two were previously arrested as part of an earlier related complaint in March: Fan “Frank” Liu and Matthew Ziburis. The third individual, Qiang “Jason” Sun, remains at large, prosecutors for the Eastern District of New York said.

Miller and Taylor were arrested in June, they said.

The charges include obstruction of justice for allegedly destroying evidence after FBI agents asked about use of a law enforcement database with information on U.S.-based Chinese dissidents.

The Chinese embassy in Washington did not immediately respond to a request for comment.