Egypt rearrests Al Jazeera reporter released last week
Under Egyptian procedure and following last week's court order, Mahmoud Hussein had been transferred from prison to a police jail to await his release.
But his lawyer, Gamal Eid, said that instead of being freed, Hussein was apparently ordered detained again in a separate case.
Eid did not know what the new charges against the journalist were, saying authorities did not notify him or Hussein's family.
Hussein's family said in a statement Tuesday the new case dates from last year, when he was already in detention.
Doha-based Al Jazeera on Wednesday criticised the rearrest of Hussein after authorities opened a new investigation against him with unspecified charges.
"It is deplorable that Mahmoud has once again been sent back to one of the notoriously deplorable prisons in Egypt," said Mostefa Souag, acting director general of Al Jazeera Media Network, referring to Tora prison in Cairo.
A spokesman for the Interior Ministry, which oversees police, did not respond to phone calls seeking comment.
Hussein, an Egyptian working for the Qatar-based satellite network, was detained at the Cairo airport in December 2016, when he arrived on a family vacation from Doha.
Since the 2013 ouster of Muslim Brotherhood President Mohamed Morsi amid mass protests against his one year rule, the Al Jazeera network has been portrayed as Egypt's national enemy for its sympathy toward Islamists, especially the outlawed Muslim Brotherhood group.
Al-Jazeera's news website has been blocked since 2017, along with dozens of other news sites deemed too critical of the government of President Abdel-Fattah al-Sisi.
Egyptian authorities also sentenced former editor-in-chief of Al Jazeera Arabic, Ibrahim Helal, to death in absentia for allegedly endangering national security.
Since his assent to power, Sisi has waged an unprecedented crackdown on dissent, arresting thousands - mostly Islamists but also prominent secular activists and journalists - and rolling back freedoms won after the 2011 uprising that toppled former leader Hosni Mubarak.
Also on Wednesday, an Egyptian court sentenced 40 suspected members of the Muslim Brotherhood group after they were convicted of wounding at least five people in 2017 in the Sharqiya province, northeast of Cairo.
They were also convicted of joining the Muslim Brotherhood, which the government designated as a terrorist group in 2013.
The verdict can be appealed.Follow us on Twitter: @The_NewArab