A Virginia couple has pleaded guilty to H-1B fraud charges in a scheme that made them millions, the U.S. Department of Justice announced Thursday.

The married couple -- Raju Kosuri, 44, and Smriti Jharia, 45 -- created a visa-for-sale system involving some 900 H-1B visa petitions over a multi-year period, according to the U.S. attorney in the Eastern District of Virginia.

Court records detail an elaborate operation that required a series of fictions to pull off.

Through a series of shell companies that purported to provide IT staffing and services to corporate clients, the defendants claimed to seek H-1B visa petitions on behalf of workers. These workers had to pay the visa fees, legal and administrative costs -- as much as $4,000 -- in violation of the visa program's rules.

When the H-1B visa workers were not on a job they were "benched" -- not paid, a practice not allowed under the program's requirements. Foreign workers are required to be paid continuously regardless of employment by an end client.

"These rules are designed to protect foreign workers from predation by American employers, to guarantee them a salary during the period of their visa eligibility, and to provide working conditions for foreign workers which will not adversely affect the working conditions of similarly employed U.S. workers," said the government, in court records.

When the visa-holding workers complained "about the difficulty of trying to live in the U.S. without income" they were told they were "nothing more than hourly consultants."

The H-1B visa workers were told to "falsify their resumes" to deceive immigration authorities about their employment history.

To explain how the phony process worked, the government cited a visa petition submitted on behalf of a person identified only as "A.G.," which claimed he would be working as a computer systems analyst for a particular company. But the supporting letter was actually written by one of the defendants in the scheme.

The guilty plea includes admitting to charges of conspiracy to defraud the United States and visa fraud, among others. As part of the case, Kosuri agreed to forfeit proceeds from the venture -- in the amount of $20.9 million.

The couple will face sentencing at a later date, a DOJ spokesperson said. The attorney representing the defendants declined to comment.

Kosuri and Jharia were indicted by a grand jury, along with four others, in April. At that time, the U.S. said they faced up to a maximum of 30 years in prison.