Investigators describe Morejon as the scheme's ringleader, accusing him of recruiting the others and paying them referral fees for each undocumented immigrant who purchased his services.

He "met with numerous illegal aliens and told them that he could assist them in obtaining their residency in the United States by pretending to be Cuban," according to a court document filed along with Morejon's guilty plea agreement last year.

"To effectuate the fraud, Morejon posed as an immigration officer to impress the illegal aliens (and) also threatened some of the illegal aliens with deportation," the document said.

The day authorities arrested him, they found blank Cuban birth certificates and altered naturalization certificates in his Florida home, federal prosecutors said in a memo filed this month. In addition to selling fake Cuban birth certificates, Morejon also sold fraudulent presidential pardons, prosecutors said.

Morejon, of Kissimmee, Florida, is scheduled to be sentenced later this month. Prosecutors have asked the judge to sentence him to more than three years in prison.

"The full extent of Morejon's fraud remains unknown as his former customers continue to be identified by the government," prosecutors said. "The one conclusion that must be drawn from all the facts is that Morejon devoted his life, over a period of more than three and a half years, to extracting as much money as possible from his customers and obtaining that money by whatever means necessary."

U.S. District Judge Cecilia M. Altonaga sentenced Ponce earlier this month to six months in prison, two years on parole and nine months under house arrest. Osorio was sentenced Thursday to four months in prison, two years of parole and 11 months under house arrest. And Silvestri was sentenced to a year in prison, three years on parole and nine months under house arrest.

Morejon pleaded guilty "and acknowledged he was the organizer," said Hugo Rodriguez, an attorney representing Morejon. That means he'll likely receive a higher sentence, Rodriguez said.

Attorney Richard Serafini, who represents Osorio, declined to comment but referred to a memo he filed in court earlier this month, arguing for a lower sentence. The memo argues that Osorio, 61, paid Morejon thousands of dollars for a fraudulent presidential pardon for her son, who had been convicted of a federal drug offense.

She became involved in the conspiracy "through her efforts to help her son" and her criminal conduct was an "extreme aberration," Serafini wrote. "Her background is one of hard work, dedication to her family and, until this episode, law-abiding," the memo said.