Metro

Son’s bad bet

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A young Upper East Side art dealer accused of leading a high-stakes betting ring was literally playing with house money — willing to wager away the prestige of his family’s $3 billion net worth and vast holdings of priceless paintings for the thrill of it all, insiders said yesterday.

“I think he was gambling away the family fortune and started playing with rough guys,” an art-world source said yesterday when asked how Hillel “Helly” Nahmad could have gone from being a Dalton School grad who partied with Leonardo DiCaprio and Orlando Bloom (above left, with Nahmad) and dated model Angela Lindvall to being an accused criminal mastermind.

A person close to Nahmad said Helly was a sports-betting fiend who would routinely wager from $100,000 to $200,000 on games, especially Knicks NBA games.

“He always sat next to Spike Lee on the floor” of Madison Square Garden with a “$200,000 bet on the game he was watching,” the Nahmad associate said.

Nahmad, 35, surrendered to federal authorities in Los Angeles Tuesday — while his gallery at the Carlyle Hotel on Madison Avenue was raided by the FBI. The feds also slapped a lien on his $50 million Trump Tower apartment, where he owns the entire 51st floor.

Charlie Finch, author of the book “Most Art Sucks,” said the arrest comes as a total surprise because “the Nahmads are like royalty in the art world.”

That reputation and money got Helly high-profile friends like DiCaprio, who while visiting Miami would routinely stay in Nahmad’s $9 million penthouse at the Bellini Bal Harbor, an associate said.

But a source who has known Nahmad for a decade was less surprised at his fall from grace.

“Every night he’s in the nightclubs, throwing around five to 10 grand on bottle service, saying he’s been going to poker tables and bragging about his winnings and how he never loses,” the source said.

Prosecutors unsealed a Manhattan federal court indictment accusing Nahmad’s and pal Ilya Trincher in a racketeering operation dating to 2006.

That allegedly included booking bets from “celebrities, professional poker players and very wealthy individuals working in the financial industry,” a criminal complaint states.

Nahmad allegedly helped launder “tens of millions of dollars” from the bookmaking ring. Nahmad’s lawyer declined to comment.

Additional reporting by Ian Mohr, Richard Johnson and Stephanie Smith