The European Union on Wednesday criticized Turkey over the rearrest of the journalist and novelist Ahmet Altan, saying the move damaged the credibility of the judiciary.
Altan was detained on Tuesday after prosecutors appealed against a court decision to free him and another veteran journalist, Nazli Ilicak, last week under supervision.
The pair were convicted of "helping a terrorist group" in connection with the failed 2016 coup to overthrow President Recep Tayyip Erdogan, though they have denied any involvement.
"The lack of credible grounds to re-arrest Ahmet Altan and his renewed imprisonment, reversing the court's initial decision to release him, further damages the credibility of Turkey's judiciary, in particular due to the high level of political interference," a spokesperson for the EU diplomatic service said in a statement.
"This interference needs to halt."
Altan and Ilicak were freed last week from sentences of 10 and a half years and eight years and nine months respectively in recognition of time served - around three years each - and ordered not to leave the country.
They were accused of ties to the outlawed group of US-based Muslim preacher Fethullah Gulen, whom Ankara accuses of ordering the failed putsch.
The EU has grown increasingly concerned at the decline in media freedom in Turkey since the attempted coup, which was followed by a major crackdown on journalists.
Turkey ranked 157 out of 180 countries in the 2019 World Press Freedom index published by Reporters Without Borders.