The United States on Thursday said it was "deeply disturbed" by the arrest by Turkish authorities of a local staff member working at its consulate in Istanbul.
The Turkish national staff member was arrested late Wednesday on charges of espionage and seeking to overthrow the constitutional order.
"We believe these allegations to be wholly without merit," the US Embassy in Ankara said in a statement, adding the Turkish government leaks to the press were "seemingly aimed at trying the employee in the media rather than in a court of law."
The embassy said "baseless, anonymous allegations" against the consulate employee undermined the relationship between the two NATO members.
The arrest, the second of a US Turkish national consulate worker this year, adds to already simmering strains between the two allies over the United States' support for Kurdish militia in Syria that Turkey considers a terrorist organization.
US investigation into Iran sanctions busting scheme
The Turkish national stands accused of having made contact with former prosecutor Zekeriya Oz, who led a 2013 corruption investigation against President Recep Tayyip Erdogan's inner circle that nearly brought down the government,
Oz fled the country after being dismissed and charges against Erdogan's inner circle were later dropped.
Turkish authorities say Oz is a member of the movement led by US-based preacher Fethullah Gulen; Erdogan accuses his former ally Gulen of orchestrating last year's failed coup attempt.
Turkey has pressed the United States to extradite Gulen.
Last month, Erdogan suggested Gulen could be swapped for American pastor Andrew Brunson, who has been in detention since October 2016 on charges of being a member of the Gulen movement. Erdogan's critics accused the president of trying to blackmail the United States.
The 2013 corruption scandal was the opening salvo in a power struggle between the government and followers of Gulen.
After seemingly going away, the corruption allegations reemerged last year when US prosecutors arrested Turkish-Iranian gold trader Reza Zarrab, a multi-millionaire power broker close to the government.
He stands accused of being behind a scheme that allowed Iran to circumvent US sanctions. Last month, US authorities also indicted Turkey's former economy minister Zafer Caglayan and the former ex-head of state-run Halk Bank on similar charges.
All three men were cleared by Turkish courts despite boxes of cash and goods being found by prosecutors and tapes becoming public that indicated an elaborate money-making plot as part of an oil-for-gold Iran sanctions-busting scheme.
The US investigation into the three men could ultimately reveal damning information about corruption and a potential cover-up by Erdogan's government. Turkey says the court cases are an American coup plot. Nearly 50,000 people have been arrested in the wake of last year's failed coup attempt and another 150,000 dismissed from their jobs.
cw/msh (dpa, Reuters)