A New York City man who breached the US Capitol building wearing a bizarre fur costume is the son of a Brooklyn Supreme Court judge, according to a report Thursday.

Aaron Mostofsky, who told The Post on Wednesday he’d come to protest a “stolen election,” was holding a police riot shield as a mob of rioters swarmed the building Wednesday.

Mostofsky is the son of Shlomo Mostofsky, a prominent figure in the Orthodox Jewish community, elected to the court last January, according to Gothamist.

On Wednesday, Aaron Mostofsky told The Post, “We were cheated. I don’t think 75 million people voted for Trump — I think it was close to 85 million. I think certain states that have been red for a long time turned blue and were stolen, like New York.”

Shlomo Mostofsky couldn’t immediately be reached for comment Thursday.

But his sibling, Nachman Mostofsky, told the outlet, “My brother did nothing illegal … He definitely was not part of the riot.”