A New York City man posing as a law enforcement agent promised a woman that he could help her get a green card if she invested $500,000 with him, prosecutors said on Friday. Instead, the man kept the money and never submitted a visa application as he had promised.

According to a federal indictment unsealed on Friday, he lied to the woman, a Chinese citizen whom the indictment names only as Jane Doe, giving her various excuses for years for why the process had been delayed.

The man, Tommy Aijie Da Silva Weng, 49, was arrested on Friday and has been charged with wire fraud, mail fraud and impersonating a federal agent. He will be detained until a bail hearing on Monday, officials said.

Prosecutors had requested he be held in detention given his extensive ties and travel to China. His lawyer, Jullian Harris-Calvin, declined to comment.

John J. Durham, the U.S. attorney for the Eastern District of New York, said in a statement on Friday that “the defendant preyed on the victim’s desire to become a United States citizen and pursue the American dream, then stole not only that dream, but also hundreds of thousands of dollars.”

According to the indictment, the scheme began when Mr. Weng met the victim in China in 2016 and told her he was a federal law enforcement officer who was seeking investors for a project building hotels in California on behalf of the U.S. government. At a later meeting, he showed her a business card from the “Federal Officers Police Association” that had his name on it.