Turkey detained on Friday the head of the board of opposition daily Cumhuriyet, which saw nine of its staff arrested last week, the newspaper said.
Akin Atalay was taken into custody at Istanbul's airport after arriving from Germany, said Cumhuriyet, which has in recent years taken a strong line against President Recep Tayyip Erdogan's ruling Islamic-rooted Justice and Development Party (AKP).
He was targeted by a warrant that was part of a probe into "terrorist activities", and was ushered into a police vehicle that was waiting for him on the tarmac.
Nine of the paper's staff, including its current editor-in-chief, were remanded in custody at the weekend pending trial after raids that have added to growing international alarm about media freedoms in Turkey.
The exiled former editor-in-chief, Can Dundar, fled to Germany earlier this year while appealing against a near six-year jail term for revealing state secrets.
Some 35,000 people have been arrested and tens of thousands more have lost their jobs -- including military officers, judges, teachers, civil servants and journalists -- in a sweeping crackdown in the wake of the failed July bid to oust Erdogan.