Jessenia Guzman, who has 13 years on the beat behind her, was slapped with a permanent reprimand placed on her record after responding casually in Spanish to a passing comment, also made in Spanish, "from a colleague on her way to get a coffee".
New York Police Department (NYPD) policy states, however, that officers are "required to communicate department business in the language of English".
An NYPD spokeswoman defended the policy, telling the New York Daily News: “We should be speaking one voice, which is English.”
Guzman is a native of New York but has family ties to the Dominican Republic.
One in three NYPD officers is Hispanic and one in five was born outside the United States.
National Latino Officers Association Director Anthony Miranda claimed that the policy is not meant to apply to "cursory greetings to co-workers".
He told NY Daily News that the four-year-old policy has only been enforced recently and cited inconsistencies, such as the fact that the officer who originally spoke to Guzman in Spanish was not reprimanded.
"It used to be a joke, when white supervisors went around and said, 'Hey, speak English,'" said Miranda.
"Now they’ve made it a rule."
Guzman has filed two federal equal opportunity complaints against the superior officer who reprimanded her.
The Spanish language hit US headlines for more positive reasons this week when the Cervantes Institute opened a Spanish-language think tank within the prestigious Harvard University.
This think tank is a first for the Cervantes Institute, a Spanish government organization which promotes both the Spanish language and Spanish Culture around the world.
Writing in Spanish daily El Confidential, José Antonio Gurpegui said the Institute should become the cultural flagship for 'Brand Spain'.
Almost 500 American students are enrolled in Hispanic studies programmes in Madrid's Instituto Franklin at the University of Alcalá de Henares and many others attend universities all across Spain.
The blog's author, director of North American studies at the university, said that "Spanish is our most valuable cultural, historical, and economic asset."