NEW YORK — Like other garment factories in New York, Jin Shun Inc. was a small enterprise on the city's margins, staffed by Chinese-speaking immigrants and tucked away in an industrial corner that few outsiders see.

There were still plenty of eyes on the factory: government regulators and monitors hired by big-name retailers to look for labor violations. Yet state labor officials who raided the shop in July said all those people who had been watching missed something — that its owners had shortchanged workers of $3 million in wages since 2005.

Monitoring programs created in the 1990s to counteract the public's outrage over sweatshops led to a new breed of scofflaws — schemers who learned to deceive their monitors in a more sophisticated fashion.

"There is an increase in contractors devising schemes to hide the violations," said New York Labor Commissioner M. Patricia Smith. "It shows the need for really aggressive enforcement."

"We've heard about folks floating around China, giving courses on how to beat the inspection programs," said Judy Gearhart, program director for Social Accountability International, a group that certifies monitoring groups worldwide.

Investigators said the New York factory, Jin Shun Inc., had schemed to deceive its many monitors, which included inspectors hired by several big-name clothing retailers that relied on the plant for production.

Among the allegations by authorities: Employees put in up to 70 hours a week while punching multiple timecards to hide their overtime. The company repeatedly changed names to avoid investigation. Workers, mostly Chinese-speaking immigrants, were even given cheat sheets, telling them how to answer questions from labor inspectors.

The cheat sheets, in Chinese, instructed workers to say they couldn't remember the details of their schedules, but always made at least $7.75 per hour.

If asked whether they liked the job, they were to respond: "I am happy here. We get along with our boss. He is very nice to us and treats us well."

Labor experts said the case illustrates the limitations of public and private programs put in place to monitor garment factories for labor abuses.

San Diego State University professor Jill Louise Esbenshade, who studied the garment industry in Southern California, said infractions are still rampant. One California survey found that more than half of the shops in monitoring programs were out of compliance with labor law.

Part of the problem, she said, was that employees had little incentive to reveal violations.

"Workers were regularly coached by contractors that if they revealed violations, everyone would get into trouble. The brand would pull the work. They would close down and no one would get paid anyway," Esbenshade said.

Lin Xue Jin, a 44-year-old seamstress in Manhattan, said she lied freely about her pay and hours whenever Department of Labor investigators visited the factory where she worked in the late 1990s.

In reality, Line said she labored up to seven days a week, 16 hours a day without a cent of overtime. Frequently, workers went weeks without being paid at all. One day, the factory abruptly closed and the owner disappeared.

Lin and other workers have spent nearly a decade trying to get thousands of dollars in back pay, mainly by suing the Manhattan company that had hired the factory to sew its clothes, Liberty Apparel.

The workers claim Liberty knew about the labor law violations because it had quality control personnel in the factory several times a week, giving instructions directly to the workers. Lawyers for Liberty say the company had limited involvement in the factory, which was an independent vendor, and owes nothing to the workers.

Major U.S. apparel retailers began creating monitoring programs in the early 1990s after many consumers complained that it wasn't enough for a company to simply deny knowledge of labor violations in the factories.

Dan Henkle, senior vice president of social responsibility for Gap Inc., said the programs have largely been a success.

Gap's team of 80 monitors conducted 4,000 inspections of 1,879 factories last year, he said, ranking each on its treatment of workers, and revoked contracts from 24 factories. Even the most well-run inspection programs can fail to turn up problems, he said.

The state said Jin Shun operated under several different names while making clothing for clients that included several national brands with comprehensive monitoring programs.

State officials identified Jin Shun's owners as two New Yorkers, Jikai Lin and Zhang Yun Chen, but a lawyer for the company insisted that Lin was just a regular factory employee making a paltry $200 per week.

The lawyer, Anthony Emengo, said Zhang Yun Chen did own the business, but only since 2005, when the previous owner abandoned the facility because of an earlier labor department investigation.

Emengo said the factory has been run cleanly since then, and called the state's charges of unpaid wages "nonsense" invented by disgruntled former employees.

"Everything is wrong," he said. "They are saying we paid workers in cash, and off the books. That's silly. Why would we do that? If we wanted to pay people off the books, why would we record it on a timecard?"