Gov. Jan Brewer (R), who oversees the agency, made national headlines in 2010 when she signed a law designed to get local and state police to investigate people who were suspected of being in the U.S. illegally.
KVOA said Figueroa may have used "a fake or forged birth certificate." Figueroa had been with Arizona DPS for 13 years.
Spokesman Bart Graves told KVOA Figueroa believed she was a citizen before being told otherwise.
"We believe the affidavit and information she gave us at the time. And, she was under the impression that she herself was an American citizen," Graves said.