Turkey on Wednesday asked the United States for information regarding the situation of a Turkish-Iranian businessman who is due to go on trial later this month in a case that has angered President Recep Tayyip Erdogan.

Reza Zarrab, 34, who holds both Turkish and Iranian citizenship, was arrested in Miami in March last year en route to Disney World on charges of violating US sanctions against Iran that could see him sentenced to up to 30 years in prison.

American media reports have said that the trial of Zarrab and fellow defendant Mehmet Hakan Atilla, the deputy chief executive of Turkish lender Halkbank, is set to get under way in New York on November 27.

But reports over the last weeks, including in the New York Times, have suggested that Zarrab may not appear in court when the trial opens.

While there has been no confirmation, this has raised speculation over Zarrab's plea.

Meanwhile, Turkish media reports said that a database had shown Zarrab to be released but this was later revealed to be technical glitch and he remains in prison.

"Our embassy in Washington has made an official request for information with the US authorities regarding Reza Zarrab following press reports," the Turkish foreign ministry said in a statement.

"We have yet to receive a response and are following the issue," it added, saying a formal diplomatic note had been sent but without giving further details.

The Hurriyet daily quoted a diplomatic source as saying Turkey had asked the US authorities to make clear in which prison Zarrab was being held and give assurances over his health and security.

Erdogan has repeatedly called on Ankara's NATO ally to release Zarrab and Atilla, with Ankara-Washington ties strained over a host of issues.

The arrest of Zarrab intrigued opponents of the government in Turkey, where Zarrab had been linked to a 2013 corruption scandal that had ensnared the elite at a time when Erdogan was prime minister.

All suspects arrested in the probe were subsequently released. Zarrab had spent 70 days in custody in Turkey over the scandal, which Erdogan denounced as a plot by the US-based Islamic preacher Fethullah Gulen to bring down his government.

Ankara now accuses Gulen of carrying out the failed 2016 coup plot aimed at ousting Erdogan, charges the preacher denies.

The American charges against Zarrab include conspiring to violate US sanctions against Iran, defraud US banks and launder money by helping Iranian entities transfer funds through US institutions. Zarrab entered a not guilty plea shortly after his arrest in April 2016.

Source: AFP