NEW YORK (Reuters) - A New York jury on Thursday ended its second day of deliberations without a verdict in the trial of a Turkish banker accused of helping Iran evade U.S. sanctions.

The jury had begun deliberating on Wednesday following the three-week trial of Mehmet Hakan Atilla, an executive at Turkey’s majority state-owned Halkbank.

The trial featured testimony from Turkish-Iranian gold trader Reza Zarrab, who pleaded guilty to charges of violating sanctions and testified for U.S. prosecutors, and from Huseyin Korkmaz, a former Turkish police officer who said he investigated Zarrab in 2012 and 2013.

Jurors on Thursday sent notes asking to review a part of Korkmaz’s testimony. They have also asked for clarification of a part of U.S. District Judge Richard Berman’s legal instructions. The jurors are expected to resume deliberations on Friday.

Zarrab testified that Atilla helped design fraudulent transactions of gold and food that allowed Iran to spend its oil and gas revenues abroad, including through U.S. financial institutions, defying U.S. sanctions.

Both Zarrab and Korkmaz implicated Turkish officials in their testimony, including President Tayyip Erdogan.

Attempts to reach Erdogan’s spokesman for comment on the allegations at the trial have been unsuccessful. Erdogan has publicly dismissed the case as a politically motivated attack on his government.

Korkmaz testified that he was jailed in retaliation for his investigation and eventually fled Turkey last year.

An Istanbul prosecutor has issued arrest warrants for Korkmaz’s parents, the Hurriyet newspaper reported on Wednesday. Korkmaz testified that he left some evidence from his investigation with his mother.

Atilla, testifying in his own defense at the trial, denied all the charges against him.

Halkbank has denied taking part in any illegal transactions.

U.S. prosecutors charged nine people in the criminal case, though only Zarrab, 34, and Atilla, 47, were arrested by U.S. authorities.