ISTANBUL (Reuters) - Turkish police summoned a Federal Bureau of Investigation (FBI) official on Wednesday over statements made in a U.S. court by a former Turkish police investigator who fled the country last year, the state-run Anadolu Agency said.

Anadolu said the FBI official was summoned following testimony given by Huseyin Korkmaz in the trial of a former executive at Turkish state-run bank Halkbank, who is charged with taking part in a scheme to help Iran evade U.S. sanctions.

State Department spokeswoman Heather Nauert confirmed that an FBI attache at the U.S. Embassy “had been brought in to the Turkish ministry”. She provided no details.

The former bank executive, Mehmet Hakan Atilla, has pleaded not guilty. Halkbank has denied involvement with any illegal transactions.

Korkmaz told jurors in a New York court on Monday that he fled Turkey in 2016 out of fear of retaliation from the government after leading a corruption investigation involving high-ranking officials. He said he took his evidence with him.

Korkmaz said he had received $50,000 from the FBI and financial assistance from U.S. prosecutors for his rental payments.

The FBI declined to comment on Wednesday.

Turkish police said they could not immediately comment on the report that they had summoned an official from the U.S. agency.

A spokesman for the U.S. embassy in Ankara said the embassy was aware of the report but had no immediate comment.

Already strained ties between NATO allies Ankara and Washington have deteriorated further over the court case, in which Turkish-Iranian gold trader Reza Zarrab, who is cooperating with U.S. prosecutors, has detailed a scheme to evade U.S. sanctions.

Korkmaz is testifying for the prosecution at the trial. He told the court this week that he began investigating Zarrab in 2012.

Zarrab has implicated top Turkish politicians, including Erdogan. Zarrab said on Thursday that when Erdogan was prime minister he authorised a transaction to help Iran evade U.S. sanctions.

Although he has not yet responded to the courtroom claims, Erdogan has dismissed the case as a politically motivated attempt, led by U.S.-based cleric Fethullah Gulen, to bring down the Turkish government.

The government blames Gulen’s network for last year’s failed military coup in Turkey. Gulen has denied any involvement.