A Long Island restaurateur who was a key witness in a public corruption investigation was sentenced to four years in prison Wednesday, ending an episode that churned up allegations of endemic wrongdoing that stretched across New York City and one of its most populous suburban areas.
Harendra Singh, 64, had pleaded guilty in 2016 to federal charges that he bribed a former Nassau County executive, Edward P. Mangano, who was once a powerful figure in local Republican politics. He testified for 17 days in two trials against Mr. Mangano, who is now serving 12 years in prison.
On Wednesday, Judge Joan M. Azrack of the Eastern District of New York called Mr. Singh “a master of pay to play.” But she credited his help to prosecutors, which revealed a dark nexus of politics and business.
“The extent and nature of his cooperation is possibly unmatched by any defendant in a corruption investigation,” Judge Azrack said. She also noted Mr. Singh’s age and health problems, as well as the support of his family, commending him for raising three successful sons. His wife, Ruby, sat in the gallery.
Mr. Singh told the judge that he was a “broken person” who had destroyed his reputation and business, and now sought to spend the rest of his days making amends.
The restaurateur admitted to trying to bribe the former mayor of New York, the Democrat Bill de Blasio, to get favorable treatment for a waterfront restaurant in the Long Island City neighborhood of Queens. That inquiry did not result in charges against the former mayor, but was a liability for Mr. de Blasio throughout his time in office — and as he mounted a doomed bid to be his party’s 2020 presidential nominee.
Mr. Singh’s testimony also exposed corruption on the other side of the political spectrum, in wealthy Nassau County enclaves long dominated by Republicans. Mr. Singh testified extensively about how he befriended local heavyweights to get ahead in business. He had been a longtime friend of the Manganos, and plied them with pricey gifts in exchange for contracts and favors.
One was a $100,000-a-year no-show job for Mr. Mangano’s wife, Linda. She was sentenced to 15 months in prison and released to home confinement in January after serving about five months.
Anthony M. La Pinta, a lawyer for Mr. Singh, said in court on Wednesday that the testimony had exposed Mr. Singh to threats and opened him to financial ruin. If there were a Mount Rushmore of cooperators, Mr. La Pinta said, “H. Singh would be front and center.”
Catherine M. Mirabile, a prosecutor, said that corruption cases were often difficult to prosecute, and Mr. Singh’s testimony was key to her team’s success in the Mangano case.
“The scale of his crimes are equaled by the scale of his cooperation,” she said.
Mr. Singh had owned at least 10 restaurants, including beach concessions in Oyster Bay. Prosecutors accused him of numerous counts of fraud and other crimes related to bribing the officials with cash, vacations, furniture, car payments and campaign contributions. In exchange, he got the town to indirectly guarantee $20 million in loans for his businesses, as well as lucrative government contracts, prosecutors said.
He was also accused of evading taxes, including paying millions to workers off the books, and of lying to the Federal Emergency Management Agency to procure nearly a million dollars in disaster-relief funds after Hurricane Sandy.
Mr. Singh also admitted to bribing a former town supervisor in Oyster Bay, John Venditto; a lawyer for the town, Frederick Mei; and other officials. Mr. Venditto, who died in 2020, was acquitted in that case, but pleaded guilty to corruption charges in state court.
Mr. Mei pleaded guilty to bribery charges and cooperated. Judge Azrack sentenced him to two years in prison Wednesday. His lawyer, Gary Schoer, declined to comment.
While federal guidelines called for a sentence as long as 17 years for Mr. Singh, Mr. La Pinta asked the court to forego additional prison time altogether. Mr. Singh spent about nine months at the Metropolitan Detention Center in Brooklyn before his guilty plea, and about three years in home confinement.
Afterward, Mr. La Pinta said he was disappointed by the judge’s decision, which he warned could have a chilling effect in cases in which people accused of crimes are considering assisting the government.
“It’s too long in light of the extent of his cooperation,” Mr. La Pinta said outside the courthouse. “This case is like no other that I’ve ever had in 31 years of doing this and no other that this courthouse has ever experienced. It’s that remarkable.”
Mr. Singh is to begin his sentence in January, and must also pay restitution — though he has said he has no money and his home is in foreclosure.
During the hearing, Judge Azrack criticized politicians who came to Mr. Singh “with their hands out” even as she marveled at the audacity of his scheming.
“The culture of corruption in Nassau County led to this day,” Judge Azrack said.
