ISTANBUL — A Turkish judge ordered a prominent journalist detained again on Tuesday — only a week after he was released — signaling President Recep Tayyip Erdogan’s intention to continue his government’s crackdown on dissent.

The journalist, Ahmet Altan , was found guilty of terrorism charges last week and sentenced to more than 10 years in jail, but he was released for time served while his case was under appeal.

Mr. Altan, 69, a former newspaper editor who wrote a novel during nearly three years of incarceration, was accused, along with the television journalist Nazli Ilicak , of sending a subliminal message during a televised interview to signal the start of the 2016 coup attempt. Mr. Altan’s brother, Mehmet, was acquitted in the case.

They were among the most prominent journalists to be detained and charged with terrorism in the widespread government crackdown that followed the failed coup: Tens of thousands of people were arrested and 150,000 public servants were purged from their jobs. The journalists have been supported by an international campaign that has highlighted the lack of press freedom and freedom of speech in Turkey.