The U.S. attorney's office says the 28-year-old actress and husband were arrested Friday for marriage fraud at their separate Los Angeles homes.
Romero also hosted the Univision reality TV show "Control."
Messages to her publicist weren't immediately returned.
Authorities contend that Romero paid 28-year-old Kent Ross to marry her in 2005 so that she could become a U.S. resident. They say the two never lived together and she submitted phony documents with her green card application.
Authorities claim that a month after the marriage, she began dating a fashion photographer and eventually lived with him.