A former operator of a New York-based immigration law firm has been extradited to the United States from Canada to face charges he led a massive immigration fraud ring that processed thousands of false immigration applications, earning millions of dollars in fees, authorities said Wednesday.

Earl Seth David, 47, was brought to New York on Tuesday to face charges including conspiracy to commit immigration fraud, conspiracy to make false statements to immigration authorities and conspiracy to commit money laundering. He was arrested in Canada on Oct. 11.

Federal prosecutors said David's firm made millions of dollars by charging high fees to illegal immigrants to fraudulently get them legal immigration status before he fled to Canada in 2006. His law firm closed in 2009.

"When he fled to Canada to avoid prosecution, Earl Seth David left thousands of victims of his alleged fraud in his wake — people who believed he was helping them secure legal status and paid him a lot of money to do so," U.S. Attorney Preet Bharara said.

Avi Moskowitz, a lawyer for David, declined to comment. His client was held without bail after an initial court appearance.

Prosecutors said David, a dual citizen of Canada and the United States, arranged for his law firm to submit at least 20,000 false immigration applications from 1996 until early 2009.

They said he charged exorbitant fees of up to $30,000 US per application to submit false claims that U.S. employers had "sponsored" the illegal immigrants for employment.

Illegal immigrants can petition under U.S. law for legal status if the U.S. Department of Labour has certified that a U.S. employer wishes to employ or "sponsor" them. The immigrant can then use that sponsorship to petition the U.S. Citizenship and Immigration Services to obtain legal status in the United States.

Prosecutors said David's firm fabricated documents, including fake pay stubs, fake tax returns and fake "experience letters," to show that the sponsorships were real.

They said the sponsors had no intention of hiring the illegal immigrants, and the sponsor companies often did not exist other than as shell companies for use in the fraudulent scheme.