A Turkish employee at the US Consulate in Istanbul is set to go on trial in March on charges of espionage and links to the failed 2016 coup against the government.
Turkey's official Anadolu news agency said Friday the first hearing against Metin Topuz would be on March 26.
Topuz, a translator and fixer for the Drug Enforcement Agency at the Istanbul consulate, is accused of links to US-based Turkish cleric Fethullah Gulen, whom Ankara blames for the 2016 coup attempt.
Topuz denies the allegations.
In January, Turkish prosecutors said they were seeking a life sentence against the suspect.
A 78-page indictment seen by The Associated Press said he was in "very intense contact" with police officers who led a 2013 anti-corruption investigation that implicated top government officials.
The indictment said Topuz told authorities he had been in touch with several police officers with alleged links to Gulen for narcotic investigations.
The prosecutor said this was a "reflexive acknowledgment of his crimes" and claimed Topuz's communication with the officers was "beyond the limits of consular work."
The indictment includes telephone calls, text messages, CCTV frame grabs with suspected police officers, along with testimonies from four witnesses and two suspects.
He is also accused of privacy violations and illegally recording personal data.
Topuz's arrest increased tensions between the two NATO allies in 2017 and led to the suspension of bilateral visa services for more than two months.
Relations hit rock bottom last summer when US President Donald Trump sanctioned two Turkish officials and increased tariffs on aluminum and steel imports, causing a huge loss in the Turkish lira's value, to pressure the country to release an imprisoned American pastor. Pastor Andrew Brunson was convicted in October for terror links but later allowed to leave the country.
Two other local consular employees are under investigation in Turkey. Jailed translator Hamza Ulucay is accused of terror group membership with alleged links to outlawed Kurdish armed groups, and staff Mete Canturk was placed under house arrest.
Ties have been on the mend since, but a host of issues remain as irritants, including US support for Kurdish groups in Syria Turkey considers terrorists, Turkey's pledge to buy Russian missile defense systems and Gulen's continued residence in Pennsylvania.
The Turkish government launched a massive crackdown against Gulen's network following the 2016 coup and arrested more than 77,000 people and sacked more than 130,000 public employees through emergency decrees.
Critics say the purge went beyond the suspects of the coup with the arrest of journalists, lawmakers and activists.