Investigators say it happened on October 13 while the agent was breaking up a fight between students on Essex Street on the Lower East Side.
Police aren't sure what substance the suspect sprayed at the 25-year-old agent.
They say he was treated at New York Downtown Hospital because it burned his eyes.
The man who sprayed the agent fled into the Essex Street/Delancey Street subway station.
Anyone with information in regard to the identity of this man is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782).
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