Pedro Ramirez, Fresno State Student President, An Undocumented Immigrant

After an anonymous e-mail revealed Fresno State Student Body President Pedro Ramirez's secret to the student newspaper, Ramirez is coming clean: He's an undocumented immigrant.

The Fresno State Collegian broke the story Tuesday, reporting that Ramirez was serving in his position without pay because of his citizenship status.

Ramirez told the Collegian that he didn't know of his situation until his senior year of high school. Ramirez came to the U.S. from Mexico at age three.

In an interview with the local ABC affiliate, Ramirez said the revelation of his secret was "a big relief." "I've been holding this in for the majority of my life," he said.

Ramirez is able to pay in-state tuition at Fresno State. He said he didn't think twice about his citizenship when running for student body president. "I'm here to serve the students," he said. "Not the state of California."

Reaction on campus to Ramirez's admission was mixed. WATCH: ABC 30's full report: