Germany has reportedly arrested a senior Al Jazeera journalist at the request of Egypt, reports said.
The Qatar-based network has demanded the immediate release of Ahmed Mansour, who works with the channel's Arabic-language service.
Monsour, who holds dual British and Egyptian citizenship, was detained by authorities at the Berlin airport while he was trying to board a flight to Qatar.
The network's acting director general Mostefa Souag said: "The crackdown on journalists by Egyptian authorities is well known. Our network, as the Arab world's most-watched, has taken the brunt of this. Other countries must not allow themselves to be tools of this media oppression, least of all those that respect freedom of the media as does Germany."
"Ahmed Mansour is one of the Arab world's most respected journalists and must be released immediately."
Mansour was arrested following an international arrest warrant that has been issued against him. He was sentenced to 15 years imprisonment in absentia by an Egyptian court in 2014.
In a press statement released by the media network, Mansour said: "I am now in detention in Berlin airport in Germany as I was heading back to Doha. We hope that this misunderstanding will be resolved quickly. It is quite ludicrous that a country like Germany would enforce and support such a request made by a dictatorial regime like the one we have in Egypt."
"I am still under arrest at Berlin airport, waiting to be taken before an investigating judge," Mansour wrote on Twitter on Saturday, 20 June.
He is expected to remain in custody until Monday, 22 June when he will face a German judge.
Egypt had accused Al Jazeera of pandering to the now-outlawed Muslim Brotherhood organisation during the uprising.