An investigation has shown a suspicious substance found inside an envelope Friday morning in the Supreme Court building in Mineola to be harmless material, authorities said.

Nassau police began a probe after a court employee made the discovery shortly after 10 a.m. and summoned court officers to the area.

“The substance was found to be benign, not a threat,” Nassau court spokesman Dan Bagnuola said around noon Friday.

Bagnuola said the granular substance fell out of juror paperwork when a court employee opened a folded piece of paper that had been inside an envelope that came in the mail.

A heavier security presence was evident in the building Friday during the investigation, but officials said court business was going on as usual except in the first floor part of the building where the item was found.

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Maduro, wife arrive for court ... Kids celebrate Three Kings Day ... Out East: Custer Institute and Observatory ... Get the latest news and more great videos at NewsdayTV

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