An investigation into a drug smuggling ring operating in states from Arizona to Massachusetts has brought in more than $13 million in narcotics and 25 alleged dealers and traffickers, authorities said.

The investigation, dubbed “Operation Dirty Dope,” began in April 2015 and involved the states of New York, Massachusetts, Pennsylvania, Arizona and New Jersey. It’s one of one of the largest heroin seizures ever in New York and is the single largest single seizure in the 46-year history of the state’s Organized Crime Task Force, according to Attorney General Eric Schneiderman’s office.

“Operation Dirty Dope is another step in our multi-faceted effort to curb the heroin crisis that is destroying our communities,” Schneiderman said. “Our message to dealers and traffickers is simple: we will not tolerate anyone smuggling death into our state.”

More than 33 kilos of heroin and 2 kilos of Fentanyl, with a total street value of more than $13 million was seized during the operation, along with 300 grams of cocaine, officials said. The bust brought in two semi-automatic handguns — including one inscribed with a drug cartel’s insignia — and eight vehicles — four of which contained sophisticated concealed compartments, or “traps,” designed for the purpose of smuggling narcotics.

According to the indictments, the ring allegedly moved most of the drugs from Mexico into Tucson, Arizona. From Arizona, the drugs were allegedly then moved in hidden compartments in cars from Arizona to the Bronx and Washington Heights in New York City, and Pennsylvania. From there, traffickers moved the drugs to sell in Suffolk County, Long Island and Leominster in central Massachusetts.

Wiretaps from the operations allegedly revealed that those charged discussed mixing other chemicals —including chicken anesthetic, Novocain, acetone (nail polish remover), roach killer (boric acid), Fentanyl, and more — in with the heroin to add to the bulk and value.

During bail arguments, it was also alleged that “traffickers used people addicted to heroin as human guinea pigs to test the quality of the cut heroin, flagrantly disregarding whether the laced heroin would kill them or not,” officials stated.

Those charged as major traffickers could face life in prison if convicted. All others could face 8 1/3 to 25 years.