NEW YORK – They run the famed Cipriani restaurants favored by celebrities like Diddy and 50 Cent.

But the father-and-son owners of the Rainbow Room and other plush Manhattan eateries Tuesday admitted there was a sleazy side to their glitzy empire – millions in tax fraud.

Family patriarch Arrigo “Harry” Cipriani, 75, and son Giuseppe, 42, the boss of their U.S. empire, agreed to pay $10 million in back taxes as they pleaded guilty to a scheme involving their offshore parent company. “The Ciprianis’ tax-evasion scheme involved illegal deductions,” said Manhattan District Attorney Robert Morgenthau.

The Cipriani restaurants, which include Cipriani Dolci in Grand Central Terminal, Downtown Cipriani and Cipriani Wall Street, employ nearly 1,000 people.

The Ciprianis rub elbows with the rich and famous, but Morgenthau called their ploy a shameless tactic to scalp hardworking average taxpayers.

Both Ciprianis pleaded guilty to tax evasion and will be placed on probation. A government auditor will oversee their books for five years.

Defense lawyer Stanley Arkin pooh-poohed the scam and insisted the Ciprianis only took the $40 million in deductions after their tax lawyer gave them the green light.

He said the father and son, who are Italian citizens, would fight any effort to strip them of their liquor licenses or deport them from the U.S. when they are formally sentenced next month.

“If you close every store in this city that had a tax issue, we’d be a ghost town,” Arkin said.

The tax-fraud probe started when prosecutors received a detailed, anonymous letter saying that Cipriani USA claimed it made $30 million in royalty payments to its parent company in Europe, even though it never really paid a dime.

The scheme allowed the Ciprianis, who were once accused of paying thousands to the mob to end a labor dispute, to avoid $4.5 million in taxes.

The same probe earlier netted Dennis Pappas, a reputed mob money adviser who was vice president of Cipriani USA.

He was sentenced last month to 1½ to 4½ years in prison for pocketing more than $1 million in bogus disability claims.

The Ciprianis were not charged in that case.

Diners at the popular restaurants shrugged off the tax scam, saying it wouldn’t keep them away from the fresh pasta and gelato.

“They’re going to pay the fine, right?” said diner John Calandra, 40, as he left Cipriani Dolci. “If they do, they’re even.”