Commodities broker Marex Group has frozen all Radiant World's accounts following allegations the iron ore trader used invalid invoices to raise funds, two sources with knowledge of the matter said.
Marex and Radiant World declined to comment.
Radiant, which also started trading base metals last year, has come under scrutiny from counterparties in recent weeks because of concerns about invoices provided to its banks.
The sources declined to be identified as the matter was not public.
LinkedIn profiles for Radiant World employees in Dubai show the company trades base metals including copper and aluminium and iron ore.
Marex is a clearing member of the London Metal Exchange, CME and Singapore Exchange and an overseas intermediary for China's Dalian Commodity Exchange and other Chinese bourses.
Radiant was founded by Pinkesh Nahar in the early 2000s, according to its website, which says the firm trades more than 20 million metric tons of iron ore annually.
Industry sources say Radiant had built up its iron ore business over the past five years and last year traded close to 75 million tons a year, worth more than $7 billion at current SGX prices .
That number compares to 60 million to 70 million tons of iron ore traded annually at Cargill and the 95 million tons traded by Glencore's marketing division last year.
