Istanbul (AFP) - The United States on Thursday said it was "deeply disturbed" over the arrest by Turkish authorities of a local staffer working at its consulate in Istanbul, saying the charges against him were baseless.
The employee was remanded in custody by an Istanbul court late Wednesday on accusations of links to the group of US-based preacher Fethullah Gulen, blamed by Ankara for last year's failed coup against President Recep Tayyip Erdogan, state-run Anadolu news agency said.
The man has been formally charged with espionage and seeking to overthrow the Turkish government, it added.
"The United States government is deeply disturbed by the arrest of a locally employed staff member," the US embassy in Ankara said in a statement.
"We believe these allegations to be wholly without merit," it added.
This is the first time a US embassy or consulate worker has been arrested as part of the investigation into the failed coup.
The statement also condemned leaks in the local press which it said came from Turkish government sources that were "seemingly aimed at trying the employee in the media rather than a court of law."
The case had been detailed earlier in the week by pro-government Turkish media, including the Aksam daily.
"Baseless, anonymous allegations against our employees undermine and devalue this longstanding relationship" between the two NATO allies, the statement said.
- 'Due legal process' -
The American embassy has repeatedly railed against unsubstantiated claims made against Washington in the pro-Erdogan press, including of a US hand in the failed coup which the United States has always denied.
The charges against the staffer relate to December 2013 corruption allegations that touched Erdogan's inner circle and the authorities claim were cooked up by Gulen in a bid to seize power.
The staffer is accused of having contact with former pro-Gulen police as well as ex-prosecutor Zekeriya Oz who was central to presenting the claims and is now a fugitive.
Erdogan's spokesman Ibrahim Kalin indicated a key figure in the case of the employee was Adil Oksuz, who Ankara believes was the top civilian leader in the coup bid but is on the run.
Kalin recalled that Turkish authorities believe a telephone call was made from the US consulate to Oksuz on the night of the failed coup.
"Since he (the employee) was detained then arrested, there must be serious evidence," Kalin told TRT Haber.
Kalin said the staffer's role in the consulate did not mean there would be a "presumption of innocence", but prosecutors would conduct the probe meticulously.
Turkey has pressed Washington for the extradition of the Pennsylvania-based Gulen, who denies any link to the coup bid.
The lack of movement on the issue has further strained ties already fraying over Washington's support for a Syrian Kurdish militia Ankara deems to be a terror group.
- 'Continue to engage' -
Turkish officials had expressed hope of a new page in Ankara-Washington relations under President Donald Trump.
But ties have strained further after members of Erdogan's security detail were indicted by US authorities after clashes with protesters during an official visit this year.
Meanwhile American pastor Andrew Brunson, who ran a church in the western city of Izmir, has been held by Turkish authorities since October 2016 on charges of being a member of Gulen's group.
Erdogan suggested last month that Turkey could release him in exchange for Gulen but Washington showed little interest in the proposal.
The American embassy said the United States will "continue to engage" with Ankara to ensure its employees and US citizens are accorded "due legal process".
Some 50,000 people have been detained under the state of emergency imposed in the wake of the failed coup, a crackdown that critics say has been excessive in scale.
Kalin insisted Turkey had never made an illegal extradition request from the US.
"We have said return these people as part of the extradition agreement. Let them be tried here" in Turkey, the spokesman said.