A leading Al Jazeera journalist was arrested at a Berlin airport on Saturday at the request of Egypt.
A lawyer for the Qatar-based satellite network said the move was part of a crackdown by Cairo on the channel.
International lawyer Saad Djebbar told Reuters Ahmed Mansour, one of the most senior journalists on the channel's Arabic service, had been abruptly and unexpectedly arrested in Germany.
A spokesman for the German Federal Police confirmed that a 52-year-old man was arrested at Berlin's Tegel airport at 1320 GMT following an international arrest warrant from the Egyptian authorities.
The spokesman said the general public prosecutor was now checking the man’s identity, as well as a possible extradition to Egypt.
Cairo’s criminal court sentenced Mr Mansour, who has dual Egyptian and British citizenship, to 15 years in prison in absentia last year on the charge of torturing a lawyer in Tahrir Square in 2011.
Al Jazeera said at the time the charge was false and an attempt to silence Mansour. “This is a very serious development,” said Mr Djebbar.
“We knew that the Egyptians were going to set such a trap to harass our journalists and that is what has happened.”
Mr Mansour was arrested as he tried to board a Qatar Airways flight from Berlin to Doha, Djebbar said.
Egyptian authorities accuse Al Jazeera of being a mouthpiece of the Muslim Brotherhood, the Qatar-backed movement which President Abdel Fattah al-Sisi toppled in 2013 when he was Egypt's army chief.
Al Jazeera is also locked in a legal battle with the Egyptian authorities to try to secure $150 million in compensation for what it says was damage to its media business inflicted by Cairo’s military-backed rulers.
In February this year, Egypt released Al Jazeera journalist Peter Greste after 400 days in prison on charges that included aiding a terrorist group.
Reuters