The network processed more than $2.5 billion through over 250 front companies across Thailand, Libya, Austria, Russia, China and Kuwait to evade sanctions, buy goods needed by North Korea and to enrich the suspects, according to an indictment filed in federal district court in Washington.

Most of those indicted were associated with a network of "covert" branches of North Korea's blacklisted Foreign Trade Bank, and included two people who had served as presidents of the bank, Ko Chol Man and Kim Song Ui, and two vice presidents.

They were accused of using front companies to clear US dollar transactions through financial networks that transit the United States, which is illegal for the Foreign Trade Bank and other entities under US nuclear and trade sanctions placed on North Korea.

In the scheme which operated from 2013 until this year, the defendants and co-conspirators "concealed FTB's involvement in US dollar payments from correspondent banks in order to trick the banks into processing the payments," the indictment said.

In terms of the number of defendants, the indictment appeared to be the largest sanctions case brought against Pyongyang yet.

There was no indication however whether any of those named could be arrested or forced to stand trial.