The publisher of Germany's Die Welt and Welt am Sonntag newspapers has filed a formal complaint at the European Court of Justice about Turkey's detention of German-Turkish journalist Deniz Yucel since February, the newspaper reported.
Turkish authorities arrested Yucel in February on charges of propaganda in support of a terrorist organisation and inciting public violence, amid a large-scale crackdown on alleged supporters of a failed military coup in Turkey a year ago.
Yucel has already filed a separate complaint with the European Court that is being supported by the German government.
Berlin has repeatedly called for the release of Yucel and other Germans being held in Turkey and the detentions have contributed to a sharp deterioration in relations between the two NATO allies.
"We are using all legal means to defend the freedom of Deniz Yucel and our publishing house to report," said Stephanie Caspar, managing director of the publisher, WeltN24 GmbH.
"It cannot be accepted without objection that a journalist is thrown into prison simply for doing his job," she added.
During Turkey's post-coup crackdown, some 150 media outlets have been shut and around 160 journalists jailed, the Turkish Journalists' Association says.
In total, authorities have jailed more than 50,000 people pending trial and suspended or dismissed some 150,000 state workers including teachers, judges and soldiers since the coup, drawing criticism from Turkey's NATO allies and rights groups.
President Tayyip Erdogan's government says the crackdown is necessary to tackle security threats facing Turkey. More than 240 people were killed in the coup attempt in July 2016.
Turkish opposition leader Kemal Kilicdaroglu told the German weekly magazine Focus that it was not safe for Germans to travel to Turkey.
"There are no security guarantees for anyone in Turkey," Kilicdaroglu, head of the secularist Republican People's Party, (CHP) told the magazine.
Kilicdaroglu, who recently completed a 25-day march from the capital Ankara to Istanbul to protest against the crackdown, said he also feared being arrested and hauled before a court, and he sharply criticised Turkey's arrest of journalists.
"I consider it completely inappropriate to designate German journalists or other citizens who come to Turkey for professional reasons as spies," he said.
Source: NAM News Network