The Obama administration has sent a harsh warning to Chinese officials about undercover Chinese intelligence agents coming to the U.S. and seeking out fugitives or immigrants.

The agents are working to bring home those the Communist government accuse of “corruption” after they gained asylum or resident status in the United States.

The declaration from the administration comes after officials discovered that Chinese hacking groups were infiltrating U.S. email databases.

Federal officials say they have found the undercover Chinese agents in the country illegally under tourist or trade visas.  These agents are using strong-arm tactics to force those the Communist government considers an enemy to return to China to be prosecuted.

Tactics include threats against family members still in China.

“Our principle is thus: Whether or not there is an agreement [with local law enforcement] in place, as long as there is information that there is a criminal suspect, we will chase them over there, we will take our work to them, anywhere,” Liu Dong, a director of Operation Fox Hunt, told the New York Times.

China and the United States do not have an extradition treaty, so the U.S. cannot force a Chinese national to return although in the past U.S. officials have returned suspected Chinese criminals.