Angwang was charged on Monday with acting as an illegal agent of China, committing wire fraud, making false statements, and obstructing an official proceeding, the Department of Justice (DOJ) said in a statement.
Angwang, who is ethnically Tibetan, had been given asylum in the United States after overstaying a visa and claiming that he'd been arrested and tortured by China "due partly to his Tibetan ethnicity", according to the criminal complaint.
CNBC reported that Angwang was born in the autonomous region of Tibet, and used his position as an officer to report back to Chinese officials "on the activities of other ethnic Tibetans in the NY area".
Prosecutors say Angwang once sought guidance from his handler after the NYPD proposed that he sit for an interview with a New York City news outlet that supports the Falun Gong, a spiritual group outlawed in China.
A 33-year-old NY police officer has been charged with acting as an illegal agent of China, with authorities here accusing the Tibetan-origin man of spying on the supporters of the Tibetan independence movement in the USA for the Chinese government.
According to the indictment, the man, who is also an officer US Army Reserve, allowed members of the Chinese consulate to attend events organised by the New York Police Department.
According to court documents, the 33-year-old also offered to provide Chinese officials with non-public information about the inner workings of the NYPD.
Angwang was assigned to the 111th Precinct located in Bayside, Queens.
But he still "maintained a relationship" with People's Republic of China officials at the consulate, including one whose department was "responsible for. neutralizing sources of potential opposition to the policies and authority of the PRC", the complaint says.
Since June 2018, the Federal Bureau of Investigation said Mr Angwang has been "in frequent communication" with an unidentified Chinese consular official he referred to as "Boss".
He is accused of being in contact with two officials at the Chinese consulate.
Assistant Attorney General for National Security John Demers said according to the allegations, the Chinese government recruited and directed Angwang, a United States citizen and member of America's largest law enforcement department, to further its intelligence gathering and repression of Chinese overseas. "The U.S. plot to discredit the Chinese consulate and personnel in the United States will not succeed".
There was no allegation that Angwang compromised national security or New York Police Department operations.
The complaint claims that Angwang "did knowingly act in the United States as an agent of a foreign government" and "without prior notification to the Attorney General of the United States, as required by law".
Prosecutors asked a judge to deny bail because Mr Angwang "presents a serious risk of flight" and is facing criminal charges which hold a maximum possible prison sentence of 55 years.