The 28-year-old actress and husband were arrested Friday at their separate Los Angeles homes and charged with marriage fraud, the U.S. attorney's office said. They contend Romero paid Kent Ross, 28, to marry her in 2005 so that she could become a U.S. resident.
Authorities said the two never lived together and Romero, whose full name is Maria Fernanda Romero Martinez, submitted phony documents with her residency application.
An investigation began after Romero's ex-boyfriend, fashion photographer Markus Klinko, told immigration authorities her marriage was a sham. The couple started dating after Romero and Ross were married.
If convicted, Romero and Ross could be sentenced to up to five years in federal prison.
Romero has had roles in several small films and is moderately well known in Mexico, where she appeared in the TV Azteca soap "Eternamente Tuya." She has also appeared on the Spanish-language channels Univision and Telemundo in the shows "Control" and "La Ley del Silencio," respectively.
According to her website, she has appeared in television and print ads for several U.S. companies, as well as a music video. She moved to Los Angeles when she was 18 to study fashion design, according to her site.
Messages to her publicist were not returned Friday.
A phone message left for Ross' attorney, Mike Shannon, also was not returned.
Romero and Ross were both released after initial court appearances Friday. However, a judge restricted Romero's travel to certain Southern California counties and said she could not leave the country.
Special Assistant U.S. Attorney James M. Left, said immigration officials began investigating in 2007 after Klinko mentioned the marriage during a lawsuit he filed in New York.
Left says a marriage ceremony was performed on June 12, 2005, but the couple never lived together.
He said immigration marriage fraud cases may be brought in either criminal or immigration courts. The case against Romero was pursued because of "the overwhelming amount of evidence" and repeated misstatements by the actress, Left said.
"Immigration benefit fraud is a serious crime," said Miguel Unzueta, an Immigration and Customs Enforcement special agent in charge in Los Angeles. "Not only does it potentially rob deserving immigrants of benefits they rightfully deserve, it also undermines the integrity of our nation's legal immigration system."