The death of Matthew Ketterer, a member of the faculty at Horace Greeley High School, was announced in an email from the Chappaqua Central School District.
Ketterer has been on paid leave since allegations came to light last year of an "inappropriate" relationship with a former student.
The popular teacher and coach resigned his position in February, effective June 30, the date his paid lead ended.
Since the news broke regarding the relationship, the district has not revealed the nature of the impropriety or the outcome of any investigation.
The details of his death or the circumstances surrounding his passing have not been made public.
In December, the district filed a request with the state Supreme Court, asking for the recent graduate to be forced to reveal the nature of the allegations under oath at an administrative hearing.
Late Tuesday, Chappaqua District Schools Superintendent Christine Ackerman informed parents, students and fellow teachers of Ketterer's death.
"I am saddened to share with you the passing of Matthew Ketterer, a social studies teacher at Horace Greeley High School and who also previously taught social studies at Seven Bridges Middle School," Ackerman wrote in an email.
"While I understand you may have questions or concerns, the family at this time is asking us to respect their privacy," she wrote. "I know this will be very difficult for some of you, please consider taking advantage of our support this week."
Ackerman also said that anyone needing support will have access to district counselors during the week from 8 a.m. to 2 p.m.
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