A Chinese woman walked into a law office in New York’s Chinatown and asked to see her lawyer. She had applied for asylum, claiming that she had been forced to get an abortion in China to comply with the country’s family-planning laws, and she was anxious about her coming interview with immigration officials.

She had good reason to be worried: Her claim, invented by her lawyer’s associates, was false.

But the lawyer, John Wang, told her to relax. The process, he said, was straightforward, and as long as she memorized a few details, everything would be fine. “You are making yourself nervous,” he said in Mandarin. “All you would be asked is the same few rubbish questions.”

“Just make it up,” the lawyer added.

The conversation, in December 2010, was secretly recorded by federal officials conducting a wide investigation of immigration fraud in New York’s Chinese population. The inquiry has led to the prosecution of at least 30 people — lawyers (including Mr. Wang), paralegals, interpreters and even an employee of a church, who is on trial, accused of coaching asylum applicants in basic tenets of Christianity to prop up their claims of religious persecution. All were charged with helping hundreds of Chinese immigrants apply for asylum using false tales of persecution.

The transcript of the conversation in Mr. Wang’s office, which was disclosed in a recent court filing, offered a rare look at the hidden side of the Chinese asylum industry in New York.