More than a dozen people are making initial appearances in a U.S. federal court in the southern state of Texas this week in connection with what prosecutors are calling a "large-scale marriage fraud scheme" that sought to use fake marriages as a way to gain permanent resident status in the United States.

So far, U.S. authorities have arrested 50 of the nearly 100 people charged with crimes that include marriage fraud, mail fraud, immigration fraud, lying under oath and witness tampering. The first trials are scheduled to begin in late June.

According to a grand jury indictment filed last week, parts of which remain sealed, the scheme operated out of Texas and involved people located both there and Vietnam.

The court filings lay out an arrangement in which those wanting to gain permanent resident status in the United States paid between $50,000 and $70,000 to an organization led by Ashley Yen Nguyen.

Those people would then be matched with a U.S. citizen recruited by the organization, who would be given a cut of the payment, and in some cases would go on to recruit other citizens to take part in the scheme as well.

To make their immigration applications seem legitimate, authorities say the organization helped those involved create albums of wedding pictures and provided fake documents relating to taxes, utility accounts and employment records.

"Marriage fraud is a serious crime," U.S. Citizen and Immigration Services Houston District Director Tony Bryson said in a statement. "USCIS remains steadfast in our commitment to ensuring national security, public safety and the integrity of the immigration system."

Prosecutors say the false nature of the marriages included spouses who have never lived together and do not intend to, ones who met briefly before applying for a marriage license if they met in person at all, and those who got married according to a financial arrangement worked out with Nguyen's organization.

"People who have been granted green cards through this fraudulent scheme, I think, will be gone after by the Department of Justice and USCIS. If they are not able to prove that their marriages were genuine, their green cards will be revoked and they will face deportation," Houston-based immigration lawyer Khanh Pham, who is familiar with the matter, told VOA's Vietnamese service.

When asked if the alleged scheme would hurt Vietnamese immigration lawyers in Texas, Khanh said yes, and that the community "has been working hard to build its reputation."

"The Vietnamese community is worried that the USCIS may tighten rules on immigration which would slow down their immigration process," Khanh said.

The process for a U.S. citizen to seek permanent resident status for a spouse is extensive, with the USCIS asking for documents such as the marriage certificate, joint lease or ownership of property, a mixing of finances, and affidavits from people asserting the marriage is bona fide.

There are also multiple forms for both the citizen and the spouse to submit, and an interview for the couple, with warnings that providing false information is subject to criminal prosecution.