Four state Registry of Motor Vehicle clerks along with two other people were arrested Wednesday after authorities say they were making false identifications through the registry and selling them to people living in the country illegally, some of whom had been deported in the past.

Some of those phony licenses and identifications were used to fraudulently register to vote in Boston, according to the U.S. Attorney's Office.

Evelyn Medina, 56, of Boston; Annette Gracia, 37, of Boston; Kimberly Jordan, 33, of Randolph; David Brimage, 46, of Boston; Bivian Yohanny Brea, 41, of Boston; and a 32-year-old man identified as John Doe were all charged in federal court with aggravated identity theft.

Officials are still trying to determine John Doe's true identity and list multiple aliases for him.

Medina, Gracia, Jordan, and Brimage were employed as clerks at the Haymarket Registry of Motor Vehicles. Authorities said Brea and Flako worked with the RMV clerks to operate the scheme.

The case against the six people began after Massachusetts State Police received an anonymous letter in October 2015 claiming a "corrupt RMV employee" was providing stolen identifications and drivers' license to people seeking the phony documents.

"An investigation revealed that several Haymarket RMV clerks - Medina, Gracia, Jordan, and Brimage - were allegedly working with Brea, who acted as the document vendor, and Flako, who acted as the document dealer, to provide licenses and identification cards to illegal aliens for cash," the U.S. Attorney's Office said.

Flako, according to authorities, worked as the document dealer. Flako allegedly sold a Puerto Rican birth certificate and U.S. Social Security card to Brea, the document vendor, for approximately $900.

Brea, in turn, sold the stolen identities for more than $2,000 to clients seeking legitimate identities in Massachusetts. These clients included people living in the country illegally, individuals who were previously deported, and an individual who admitted to previously facing drug charges.

Brea allegedly also used the fake documents to register people to vote in Boston. The four RMV workers are accused of accepted cash to illegally issue authentic RMV documents - licenses and identification cards.

"The clerks also accepted cash to use the RMV's system to run queries, including Social Security number audits, to confirm that the identities the clients were stealing actually belonged to verifiable individuals," the U.S. Attorney's Office said.

The investigation into the corruption and identity theft scheme is ongoing.