Confidential bank documents show how firms linked to Kim Jong-un’s hermit kingdom suspiciously transferred money in bursts, sometimes only days or hours apart. Many of the companies in question had opaque ownership.
The papers reviewed by NBC News suggest the practice continued for years.
And Chinese firms helped with the covert process, the documents suggest.
The money was moved through prominent banks in New York for no clear commercial reason.
The amounts shifted were in round figures.
Graham Barrow, a British anti-money laundering expert, said the transactions outlined in the documents amounted to “red flags”.
Mr Barrow, who is based in London, said the information contained in the bank papers clearly pointed to parties’ efforts to conceal the origins of illicit money.
The documents cover a period mainly from 2008 to 2017.
READ MORE: WW3: Iran could have ‘nuclear weapon by the end of the year’
On Sunday it emerged the Trump administration is planning to slap sanctions on more than two dozen people and entities involved in Iran’s nuclear, missile and conventional arms programs.
The plan was announced by a senior US official.
President Trump, who is gearing up for the November 3 election, is keen to be seen to be taking strong actions against America’s foes.
The move will put teeth behind UN sanctions on Tehran that Washington argues have resumed despite the opposition of allies and adversaries.
Speaking on condition of anonymity, the official said Iran could have enough fissile material for a nuclear weapon by the end of the year.
The source said that Tehran has resumed long-range missile cooperation with nuclear-armed North Korea.
He did not provide detailed evidence regarding either assertion.
The new sanctions fit into Mr Trump’s effort to limit Iran’s regional influence.
The round of penalties comes a week after US-brokered deals for the United Arab Emirates and Bahrain to normalise ties with Israel, pacts that may coalesce a wider coalition against
Iran while appealing to pro-Israel voters ahead of the presidential election.