"It can be confirmed that Eva M. Michelmann was released this morning and returned to Germany this afternoon," Roland Meister said.

Michelmann was able to leave Syria via a third country and from there boarded a flight to Germany, according to a report in Der Spiegel magazine.

The journalist initially went missing during an offensive by Syrian government fighters in the northeast of Syria, which had previously been controlled by Kurdish forces.

Reports at the time said she had been taken in a vehicle belonging to government troops in the city of Raqqa, along with Turkish-Kurdish journalist Ahmed Polad.

According to the Committee to Protect Journalists (CPJ), they both worked for the Istanbul-based socialist Etkin News Agency (ETHA) and the Ozgur TV channel.

The German foreign ministry last week said it was making "intensive representations" in the case at a "high level" and had been able to make visits to Michelmann in detention.

However, the ministry did not say why Michelmann was being detained or whether Syrian authorities had charged her with any crime.

Meister told AFP last week that he had received reports of Michelmann being "tortured and subjected to constant interrogation, including at night" and that she had "lost a lot of weight".

The CPJ had condemned "the Syrian government's lack of transparency regarding the detention and whereabouts" of the two journalists as "unacceptable".