The pan-Arab television network Al Jazeera said on Sunday that one of its best known journalists, Ahmed Mansour, had been ordered to remain in custody after appearing before a judge in Germany.
Mansour was arrested in Berlin at Egypt's request, in a case that could embarrass Germany and renew questions about Cairo's crackdown on dissent.
Egypt accuses Al Jazeera of being a mouthpiece of the Muslim Brotherhood, the Qatar-backed Islamist movement that President Abdel Fattah al-Sisi removed from power in 2013 when he was army chief and calls a terrorist group.
Both the television channel and the Brotherhood reject the allegations made by Egyptian authorities.
Mansour, a leading talk show host on the Qatari channel's Arabic service, was arrested at a Berlin airport on Saturday, the latest Al Jazeera journalist to be pursued by the Egyptian authorities.
"The temporary detention investigative judge has concluded his investigation with Ahmed Mansour and he has been transferred to Moabit prison in Berlin," Al Jazeera said on its website on Sunday.
A Cairo court sentenced Mansour, who has dual Egyptian and British citizenship, to 15 years in prison in absentia last year on a charge of torturing a lawyer in 2011 in Tahrir Square, the focus of the uprising that toppled veteran autocrat Hosni Mubarak.
Jazeera said at the time the charge was false and an attempt to silence Mansour, known to viewers across the Arab world.
Mansour told Al Jazeera by telephone earlier: "The German authorities told me that we are dealing with an international criminal case" and a judge would decide whether he should be extradited to Egypt.
Egyptian Foreign Ministry spokesman Badr Abdelatty said Cairo was liaising with the German authorities.
"He is accused of a crime and was sentenced so of course we have called for him to be returned," he told Reuters.
Critics accuse the West of turning a blind eye toward what they say is Egypt's crackdown on dissent and freedom of speech in favor of improved economic ties and security cooperation.
Mansour's arrest may bring to a head Germany's divisions over how to deal with Egypt, a country that is a valuable political ally and business partner, but also accused of widespread human rights abuses.
Sisi visited Germany this month at Chancellor Angela Merkel's invitation, but the speaker of Germany's parliament canceled a meeting with him, citing rights violations in Egypt.
Also during the visit, German company Siemens signed an 8-billion-euro deal ($9 billion) with Egypt to supply gas and wind power plants.
"The arrest of (Mansour) throws up many questions which need to be cleared up as soon as possible since Germany must not be a henchman of Egypt's politically controlled justice system," Niels Annen, foreign policy spokesman for the Social Democrats in the German parliament, told Spiegel Online.
Egypt released Australian Al Jazeera journalist Peter Greste in February this year after 400 days in prison on charges that included aiding a terrorist group.
Mohamed Fahmy, a naturalized Canadian who has given up his Egyptian citizenship, and Egyptian Baher Mohamed were released on bail in February after spending more than a year in custody.
The journalists were originally sentenced to between seven and 10 years in prison on charges including spreading lies to help a terrorist organization, which they have denied.
Egypt's high court ordered a retrial in January.
(Additional reporting by Omar Fahmy in Cairo and Caroline Copley in Berlin; Writing by Michael Georgy, Editing by Rosalind Russell)