A powerful New York jail union boss-turned-prison inmate is poised to go free less than halfway through his sentence in a corruption case, after a judge decided this week that the nearly five-year term should be reduced.

Norman Seabrook originally was sentenced to 58 months in prison on his federal conviction for taking bribes to put $20 million in union pension money into a risky hedge fund. The union lost $19 million.

But U.S. District Judge Alvin K. Hellerstein said Seabrook’s sentence is now unfair — because a co-defendant appealed and got his own prison term reduced to just over a year.

“There is now an unjust disparity” between the defendants’ sentences, Hellerstein wrote in an opinion Thursday. Hellerstein himself originally sentenced both defendants.

Seabrook, 63, has served about 21 months. He remains in custody for now, as Hellerstein put the ruling on hold for 10 days while prosecutors decide whether to appeal.

Messages were sent Saturday to prosecutors and Seabrook’s attorneys.

As head of the New York City Correction Officers’ Benevolent Association for two decades, Seabrook became a political powerbroker and held huge influence over how the city’s Rikers Island jail complex operated. He made as much as $300,000 per year.

Prosecutors said he accepted a $60,000 kickback — delivered in a luxury Ferragamo handbag — in exchange for getting the union to invest in the hedge fund. Seabrook maintained that he did nothing wrong, and that the union simply made a bad investment.

After a 2017 mistrial, Seabrook wasconvicted the next year, though he ultimately didn’t have to report to prison until May 2021.

Meanwhile, co-defendant Murray Huberfeld, a principal in the hedge fund, pleaded guilty to arranging the payoff.

Hellerstein sentenced Huberfeld to 30 months, aiming for “approximate equivalence” between his and Seabrook’s punishment, as the judge explained in Thursday’s ruling.

Then Huberfeld successfully appealed his sentence, which was trimmed to 13 months.

In light of that development, Hellerstein concluded that releasing Seabrook now “reflects the seriousness of Seabrook’s crime and lack of timely acceptance of responsibility, while also remedying what would otherwise be an unjust sentencing disparity” between the defendants.

Whenever Seabrook is released, he will owe $19 million in restitution to the union.

(AP)