Federal authorities have arrested and extradited five members of an alleged Asian drug ring in Thailand and charged them with conspiring to smuggled 100 kilos of North Korean methamphetamine into the U.S. The bust was connected to the arrest in September of a former U.S. Army sharpshooter nicknamed "Rambo," a federal law enforcement source told NBC News.

The five defendants, who hail from the U.K., China, the Philippines and Thailand, were arrested in Thailand in September, arrived in New York Tuesday night and were scheduled to appear in a Manhattan courtroom Wednesday.

“Methamphetamine is a dangerous, potentially deadly drug drug, whatever its origin,” said Preet Bharara, U.S. Attorney for the Southern District of New York. “The threat it poses to public health is grave whether it is produced in New York, elsewhere in the U.S., or in North Korea. This investigation shows our determination to close a potential floodgate of supply.”

In 2012, according to prosecutors, Ye Tiong Tan Lim, 51, and Kelly Allan Reyes Peralta, 41, alleged members of a Hong Kong-based criminal organization, sold more than 30 kilos of meth produced in North Korea to a customer. Scott Stammers, 44, and Philip Shackels, 30, both U.K. citizens, were responsible for storing the drug after sale. Law enforcement agents later seized the 30 kilos of North Korean meth, which tested at 99 percent pure, in Thailand and the Philippines.

In 2013, Lim and Reyes Peralta allegedly greed to provide 100 kilos of North Korean meth to confidential sources working for the U.S. Drug Enforcement Administration. According to prosecutors, Lim, a Chinese national, told customers that only his group could obtain North Korean meth because the North Korean regime had destroyed most of the country’s labs as a gesture of good will to the U.S. “The (government) already burned all the labs,” Lim allegedly said. “Only our labs are not closed.”

Lim allegedly claimed that his organization had stockpiled a ton of North Korean meth.

Lim and Peralta, a Philippine national, allegedly agreed to deliver the 100 kilos of meth in Thailand, from where they understood it would be shipped to the U.S. Stammers, Shackels and a fifth defendant, 43-year-old Alexander Lnu of Thailand, agreed to provide storage and transportation for the drug inside Thailand. Lnu, also known as Alexander Checov, was the sergeant-at-arms of a local motorcycle gang and was the alleged “ground commander” supervising a group of bikers guarding the stash. The two Brits were allegedly supposed to package and deliver the drug to a marina in Thailand, where it would be transferred to a U.S.-bound boat.

All five men were arrested by Thai law enforcement on Sept. 25. Each has been charged with conspiracy to import methamphetamine to the U.S. and would face a mandatory minimum of 10 years in prison and up to life imprisonment if convicted.

The law enforcement source, who spoke on condition of anonymity, said the arrests were related to a case brought against former U.S. Army Sgt. Joseph "Rambo" Hunter, 48, who was accused in September of leading a ring of globe-trotting contract killers who worked for drug traffickers.

Court papers outlined a plot to assassinate a Drug Enforcement Administration agent and an informant in Liberia for $800,000. two men who allegedly worked for Hunter -- a German sniper and a U.S. Army veteran -- were arrested in Liberia. Two more alleged co-conspirators were arrested in Estonia.

Hunter was accused of quarterbacking the operation from Thailand. He was arrested in Phuket.

NBC News Justice Correspondent Pete Williams contributed to this report.

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