Authorities have charged 18 people in an alleged scam in which Americans were paid to marry Eastern Europeans so the immigrants could get legal residency.

A federal indictment unsealed Monday charges nine Americans and nine Eastern Europeans with marriage fraud. The U.S. defendants also were charged with conspiracy to commit immigration fraud.

According to the indictment, the Americans accepted payments of up to $5,000 to enter into bogus marriages with the Eastern Europeans. The defendants attended each other's weddings and posed in photos to make the arrangements appear legitimate to immigration authorities, the indictment said.

Jeremy Starnes, 31, of Chicago is accused of leading the scheme. He pleaded not guilty Monday.

Starnes allegedly promised U.S. citizens involved in the scam $1,000 the day of the marriage, $1,000 three months later, $2,000 after an interview with immigration officials and $1,000 after the immigrant received permanent residency status.

There was no comment from Starnes; no phone numbers were listed under his name in Chicago. His attorney, Charles Aron, did not immediately return a call seeking comment Tuesday.

If convicted, each defendant could face up to five years in prison.