The alleged incident occurred at Harbor Island Park and was reported to authorities around 6:30 p.m. Wednesday.
The unidentified boy was arrested and charged with first-degree sexual abuse early Thursday, police said.
A camp official referred questions about the incident to the police, but did say Thursday that the counselor no longer works there.
The charges are being investigated by village police with the help of the Westchester County District Attorney’s Office.
No further details, such as the victim’s age or the exact nature of the alleged assault, were available at press time.
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