Mehmet Hakan Atilla, a former banking executive in Turkey whose co-defendant in an Iran sanctions-busting case became the star witness against him, has been found guilty of five of six counts after a roughly monthlong trial.

A federal jury in Manhattan found Atilla, 47, guilty of conspiracy to defraud the United States, conspiracy to violate the International Emergency Economic Powers Act, conspiracy to commit money laundering, bank fraud and a related conspiracy count.

But the jury acquitted Atilla on one count of money laundering. U.S. District Judge Richard Berman of the Southern District of New York presided over the case.

Atilla, who previously served as deputy CEO of the Turkish state-run Halkbank, was accused of helping to orchestrate complex schemes to help Iranian institutions circumnavigate proceeds from oil and gas sales around U.S. sanctions by purchasing gold and fraudulently designing transactions to look like purchases of food and medicine by Iranian citizens, according to the indictment against him and other alleged participants in the scheme.

Among them was Reza Zarrab, a gold trader who holds citizenships in Turkey, Iran and Macedonia who pleaded guilty in October to six counts related to the sanctions-avoidance scheme and one count of attempting to bribe a corrections officer to gain access to a cellphone and to have alcohol smuggled into a federal detention center.

Before he began working with prosecutors, Zarrab had hired former New York City Mayor Rudolph Giuliani and former U.S. Attorney General Michael Mukasey onto his defense team to meet with Turkish President Recep Tayyip Erdogan to seek a diplomatic solution to the case.