A wealthy Turkish-Iranian gold trader is set to testify at a New York trial about how he helped Iran evade U.S. economic sanctions.
Prosecutors say Reza Zarrab likely will take the stand Wednesday and will be a key witness against Turkish banker Mehmet Hakan Atilla.
Court papers show Zarrab pleaded guilty last month to bank fraud, money laundering and other charges as part of a deal to testify.
Prosecutors say Zarrab and Atilla laundered Iranian oil money in violation of U.S. economic sanctions against Iran. They say the conspiracy involved bribes and kickbacks to high-level officials.
Atilla has pleaded not guilty.
Prosecutors had kept secret that Zarrab was cooperating in a bid for leniency. Atilla's lawyer says the trial is about Zarrab's crimes.