An Egyptian prison official and the nation's official news agency said Greste was released following a presidential "approval." The official and an Interior Ministry statement said his release was an implementation of the new deportation law passed last year. The officials spoke on condition of anonymity because they were not authorized to speak to the media.
Greste, Egyptian-Canadian Mohammed Fahmy and Egyptian Baher Mohammed were sentenced to at least seven years in prison on terrorism-related charges last year in a trial described as a sham by rights groups. There was no immediate word on the other two journalists.
The release of Greste, 49, who also holds Latvian nationality, was welcomed by Al-Jazeera and Amnesty International, but both said the fate of the other journalists must not be forgotten.
Acting Al-Jazeera Director General Mostefa Souag says the Qatar-based network "will not rest until Baher and Mohamed also regain their freedom."
Hassiba Hadj Sahraoui, Amnesty International's Deputy Director for the Middle East and North Africa, welcomed the news of Greste's release but said "nothing can make up for his ordeal."
"It is vital that in the celebratory fanfare surrounding his deportation the world does not forget the continuing ordeal of Baher Mohamed and Mohamed Fahmy, who remain behind bars at Tora prison in Cairo."
The three were arrested over their coverage of the violent crackdown on Islamist protests following the military overthrow of President Mohammed Morsi in 2013. Egyptian authorities accused them of providing a platform for Morsi's Muslim Brotherhood, now declared a terrorist organization.
The three were also convicted for spreading false information, faking reports to show that the country was on the verge of civil war, and for aiding the Brotherhood's goal of portraying Egypt as a failed state. Mohammed received an additional three years for his possession of a spent bullet. Three other foreign reporters received a 10-year sentence in absentia. Twelve other co-defendants were sentenced to between seven and ten years, some of them in absentia.
Rights groups and several media outlets condemned the verdicts as political, saying the three were doing their job during a tumultuous time.
According to a law passed late last year, Egyptian President Abdel-Fattah el-Sissi has the power to deport foreign defendants or convicts if it's considered to be in the interest of national security. The law was seen as providing a potential legal instrument with which to free the journalists.
El-Sissi had repeatedly said he wants to end the case, which has prompted a storm of international criticism.
Greste had only been in Egypt for weeks, working on a short relief for his colleagues, when he was detained.
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