Three of Al Jazeera's journalists have been held in custody in Egypt since December 29, accused of spreading lies harmful to state security and joining a terrorist organisation, according to the prosecutor.
Producers Mohamed Fahmy and Baher Mohamed, and correspondent Peter Greste were arrested along with cameraman Mohamed Fawzy, who was later released.
Al Jazeera denies the accusations against its team and has expressed outrage at the continued detention of its journalists without charge.
The broadcaster is becoming increasingly concerned about the safety of its staff members as their imprisonment continues.
Producers Mohamed Fahmy and Baher Mohamed, and correspondent Peter Greste have faced questioning since they were detained, but have still not been officially charged.
No news on their release has been given by the authorities in Egypt.
Greste has twice appeared in front of the prosecutor in Cairo, but is still being detained.
A legal adviser said that Mohamed will be detained in Tora prison, outside Cairo, until he is brought before a prosecutor for questioning. This was due to happen on Saturday.
Fahmy, who has also been detained in Tora prison, has been moved to a prison hospital where he is being treated for an injury he suffered before his arrest. He was expected to undergo further questioning on Sunday, along with Greste.
'False and unfounded'
Al Anstey, managing director of Al Jazeera English, said: "It is outrageous to be treating bone fide journalists in this way. The allegations that are being made are totally false and unfounded.
"We operate in Egypt legally. The team were working on a number of stories to show our viewers around the world all aspects of the ongoing situation in the country, and every member of our team has huge experience carrying out the highest quality journalism with integrity."
Greste is an award-winning journalist who joined Al Jazeera English after working with CNN and BBC. He won the Peabody Award in 2012 for his documentary on Somalia.
Fahmy worked for CNN and the New York Times before joining Al Jazeera.
Mohamed works as a Cairo-based producer for Al Jazeera English.
All three Al Jazeera journalists have upheld the highest standards throughout their careers.
Heather Allan, head of newsgathering at Al Jazeera English, said: "Peter and the team have been working on a number of stories in Egypt. We reported daily on political events including the recent protests in some universities.
"The team also covered the problems of traffic congestion in Cairo, and the cancellation of the Egyptian football league. We have been covering a variety of different stories from the country as we always do."
Two other Al Jazeera journalists, Abdulla al-Shami and Mohamed Badr, have been held without charge for more than five months. The network has been also demanding their immediate release.
Several organisations involved in global media freedom have joined the call for their immediate and unconditional release including: Committee for Protection of Journalists, Reporters Without Borders and International News Safety Institute.