An open letter was issued on Tuesday by several international news organisations pleading for the release of Australian journalist Peter Greste, who has been detained in Egypt since December.
The letter was signed by Greste’s former employers at BBC, ITN, Reuters, Sky News, NBC and ABC.
“We know Peter Greste to be a fine, upstanding correspondent who has proved his impartiality over many years, whichever of our organisations he has been working for, and in whichever country,” the letter said, stressing that regardless of conditions in Egypt, freedom of speech should remain the fundamental principle of any country.
The letter urged Egyptian authorities to release Greste and the 19 other detained journalists – 16 Egyptians and three foreigners.
Calling the journalists' arrest "unjust and unacceptable," the letter said that the incident was "deeply damaging to the future of impartial journalism in the country."
Greste, an award-winning reporter, has been in custody along with Al-Jazeera's Cairo bureau chief Mohammed Fahmy and Egyptian producer Baher Mohamed since late December after being arrested at a Cairo hotel.
All 20 journalists were referred to criminal court on 29 January.
The 16 Egyptian defendants face charges of belonging to a terrorist organisation, while the four foreigners -- Greste, two English and one Dutch -- are accused of aiding the terrorist group and spreading false news.
Last month, Greste released a letter from Tora prison in Cairo where he is being held, describing the harsh conditions and criticising the authorities for the arrests.
"The state will not tolerate hearing from the Muslim Brotherhood or any other critical voices. The prisons are overflowing with anyone who opposes or challenges the government," he said. "So our arrest is not a mistake, and as a journalist this is my battle."
Egyptian authorities accuse the Al-Jazeera network of giving favourable coverage to the Muslim Brotherhood group, deemed a terrorist organisation by authorities in December.
Al-Jazeera's Cairo offices have been shut down since 3 July, after being raided by security forces in the immediate aftermath of the ouster of president Mohamed Morsi, who hails from the Brotherhood.
The only Al Jazeera-affiliated channel to have been banned with a court order is Al-Jazeera Mubasher Misr. All other sub-channels were closed illegally.
The crackdown on journalists following Morsi's ouster has provoked an international outcry and has been condemned by international rights groups and media organisations.