ISTANBUL (Reuters) - A Turkish court ruled on Thursday to keep U.S. consulate employee Metin Topuz in jail until his trial resumes on May 15, a lawyer for Topuz said on Thursday.

The lawyer Halit Akalp said he will appeal the decision. “Under normal circumstances, and in the light of existing evidence, Topuz should have been released today,” Akalp said.

“We will exercise our right to appeal and then the decision will be for the higher court to make. Whether they release or not, we will wait for May 15th.”

The trial of Topuz, a Turkish translator and fixer for the Drug Enforcement Agency (DEA) at the U.S. consulate in Istanbul, has deepened strains in the already fraught ties between NATO allies Turkey and the United States.

Topuz is on trial for charges of espionage and links to the network that Turkey says orchestrated a 2016 attempted military coup. Washington says Topuz is innocent. His arrest in 2017 led to a months-long suspension of visa services between the two countries.

Speaking from the Istanbul court, U.S. consul general Jennifer Davis said: “We did not see today in this hearing any evidence of criminal wrongdoing on the part of Metin Topuz, and we reiterate our government’s call for the swift and fair resolution of this case.”

Akalp had said earlier that he expected his client to be released on bail on Thursday. “We will set forth our demands today and the court will form a decision. We expect him to be released,” he said outside a courtroom shortly before the start of the third day of his trial.

In a 78-page indictment which includes telephone calls, text messages and CCTV images, Topuz is accused of links to officers who led a 2013 corruption investigation that implicated officials in the government of then-prime minister Tayyip Erdogan, who is now president.

Topuz denies the charges, saying it was not his decision who he came into contact with through his work.

Already detained for 17 months since his arrest in October 2017, Topuz faces life in jail if found guilty of espionage and attempting to overthrow Turkey’s government.

The court on Wednesday heard from witnesses named in the indictment, some of whom are also on trial on charges related to the July 2016 coup attempt.