A Turkish employee of the United States consulate in Istanbul went on trial on Tuesday, more than 17 months after he was jailed over alleged ties to Turkey's 2016 failed coup.

Metin Topuz, a US Drug Enforcement Agency (DEA) staffer, is accused of espionage and links to the US-based cleric Fetullah Gulen, the man Turkey's government believes was behind the attempted putsch — a claim Gulen strongly denies.

Prosecutors concluded that Topuz had "very intense" contact with police chiefs who led a 2013 corruption probe against President Recep Tayyip Erdogan's inner circle and top government officials. The police chiefs also are accused of links to Gulen.

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'Selective investigations'

Topuz explained that his work for the DEA involved contacts with Turkish security forces, arguing that the prosecutor only examined contacts he had with officers allegedly linked to Gulen and ignored conversations he had with hundreds of other officers.

"During my 25 years of work with the DEA, I have met many police officers and public officials, exchanging numbers and business cards," Topuz said in his trial testimony.

Topuz said he cannot be expected to know or identify officers with alleged links to Gulen. Turkey has appealed, so far in vain, for the US to extradite Gulen, who is a legal resident of Pennsylvania.

Read more: Turkey 'seeking arrest of second US consulate worker'

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NATO partners adrift: USA and Turkey Turkey arrests US consulate employee October 5: Turkish authorities arrest Metin Topuz, a Turkish national employed at the US consulate in Istanbul. He is formally charged with espionage and collaboration in the 2016 coup attempt. The US embassy in Ankara subsequently says it is "deeply disturbed" by the arrest. It's reportedly the second since March, when a Turkish US consulate employee was arrested in Adana.

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Tit-for-tat spat

Topuz's arrest triggered a diplomatic spat which led to the United States halting full visa services to Turkish nationals. Turkey responded with a tit-for-tat move halting visa services to US citizens.

Topuz, 59, was hired at the consulate in 1982 as a switchboard operator and progressed to a position as assistant and translator to the DEA's American personnel in Turkey a decade later.

Prosecutors are seeking life imprisonment for Topuz, who denies the allegations. The first hearing is expected to continue until Thursday.

Read more: US, Turkey resume visa services halted by diplomatic spat

Watch video 00:56 Turkey's Erdogan says US decision to suspend visa services 'upsetting'

kw/rt (AP, AFP, dpa)

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