WeltN24, the parent company of Germany's "Die Welt" newspaper, filed the complaint on Wednesday with Turkey's top court over the detention of its correspondent.

"We will use all legal means at our disposal to defend the reporting freedom of our correspondent and our publishing company," Stephanie Caspar, the chief executive of WeltN24, said Wednesday.

Yucel was taken into custody on February 14 before being placed in pre-trial detention in late February. Since March 1 he has been in solitary confinement at the high security Silivri prison outside Istanbul.

The Turkish and German passport holder stands accused of supporting "terrorist propaganda" and "inciting" the public to violence.

Authorities initially detained the dual German-Turkish national after he reported on a trove of emails released by leftist hacker group Redhack that was allegedly from the private account of Berat Albayrak, the country's energy minister and the son-in-law of President Recep Tayyip Erdogan. The emails detail Turkish support for Syrian jihadist rebel groups and attempts to control the media.

Erdogan has accused Yucel of being a German "spy" and agent of the outlawed Kurdistan Workers' Party (PKK).

Turkish law allows for pre-trial detention of up to five years.

More than 100 journalists are languishing in Turkish prisons, mostly on trumped up terrorism charges. 

Wednesday's court action comes a day after a Turkish court ruled to keep six human rights defenders in pre-trial detention on terror related charges.  

Among those remanded in detention were German human rights consultant Peter Steudtner and Amnesty International's director for Turkey, Idil Eser. 

Turkey has long struggled with the rule of law and an independent judiciary, but the scale of its politicization has increased in the wake of last July's failed coup attempt and mass purges.