A potent new fentanyl derivative known as “White China” that isn’t yet illegal in New York is helping to drive a spike in overdose deaths locally, NYPD officials and Brooklyn prosecutors said Wednesday as they announced charges against a drug trafficking gang with links to the Bloods.

Furanyl fentanyl, the derivative the ring was distributing in Brooklyn, was manufactured in China and can be up to 50 times more potent than heroin, Acting Brooklyn District Attorney Eric Gonzalez told reporters at a news conference.

“These synthetics are lethal, they are cheap and they continue to flow into our streets,” Gonzalez said.

NYPD Chief of Detectives Robert Boyce said police believed the new fentanyl compound had been ordered from China over an encrypted part of the internet — the so-called “dark web” — and shipped from a supplier in Arizona to the Brooklyn drug ring.

Because the compound is so new, he said, it was just added to the federal list of illegal controlled substances late last year, and still hasn’t been made illegal by New York State. Prosecutors charged the ring with attempted sale of an illegal drug on the theory that many buyers thought the knockoff actually was heroin.

“That’s something the lawmakers need to work on in Albany,” Boyce said.

In a 357-count indictment in Brooklyn Supreme Court, prosecutors charged Nigel Maloney of Phoenix as the primary supplier of heroin, cocaine and the fentanyl to the Brooklyn ring, which was allegedly headed by Jerome Horton and Willie Billingslea of East New York.

The 34 members of the ring charged in the indictment included three Long Islanders: Christopher Corley, 40, of Freeport, Jackie Hillard, 43, of Ronkonkoma, and Micky Hilton, 36, of Rockville Centre.

Officials said the ring was raking in $1 million a year, and they seized $300,000 in cash, 13 firearms, and 4.5 kilograms of furanyl fentanyl along with 2.4 kilograms of cocaine and 1.7 kilograms of heroin.

The fentanyl derivative, officials said, sells for as little as $7 an envelope, but its potency has led to an increase in addiction rates and demand from users for increasingly pure heroin. During the past year, overdose deaths have more than tripled the number of homicides in the city.

“You do the numbers,” Boyce said. “This is the crisis we have.”