Tablets suspected to be fentanyl are placed on a graph to measure their size at the Drug Enforcement Administration Northeast Regional Laboratory in New York. Photo: AFP / Don Emmert

The US Treasury Department named four individuals and one company as important figures in a leading Chinese fentanyl manufacturing and trafficking group, boosting pressure on China to take action against it.

The Treasury said Ji Songyan, Zhan Longbao, Cheng Guifeng and Zheng Guangfu as well as Global United Biotechnology Inc. were all part of the Shanghai-based Zheng drug trafficking organization headed by Zheng Fujing, who was indicted by the Justice dDepartment in 2018.

Zheng’s gang, according to the Treasury, has produced and shipped large amounts of deadly synthetic opioids like fentanyl and carfentanil, which is 100 times more potent than fentanyl, to the United States where they fuel an epidemic of addiction and overdoses.

The four Chinese named Friday to the Treasury sanctions blacklist have been instrumental in facilitating payments for the Zheng group, it said.

Global United Biotechnology is run by Zheng as “a virtual storefront” for the trafficking group, which processes payments using virtual currencies like bitcoin to launder proceeds through China and Hong Kong-based companies, it said.

The Treasury did not say whether China, amid deteriorating relations with the United States, has taken action against the group.

Zheng Fujing “remains in China,” it said in a statement.