It was the latest move against the Qatar-based broadcaster which Egypt accuses of supporting the outlawed Muslim Brotherhood.
It was the latest move against the Qatar-based broadcaster which Egypt accuses of supporting the outlawed Muslim Brotherhood of ousted president Mohamed Morsi.
Egyptian Mahmoud Hussein, 51, flew to Cairo on Tuesday for a family holiday but was stopped and interrogated at the airport for several hours before being released.
On Friday, police raided his Cairo home and arrested him. He was questioned again on Saturday and Sunday, when prosecutors decided to hold him for 15 days.
The prosecution official said Hussein would be held "pending an investigation into accusations that he incited against the state and broadcast fake news and documentaries".
The interior ministry confirmed the accusations in a statement posted on its Facebook page.
It said Hussein was implicated in an Al-Jazeera "plot" aimed at "fomenting discord and inciting against state institutions... and broadcasting false news as well as fabricated news reports and documentaries".
In November, Al-Jazeera broadcast a documentary called "The Soldiers" in which former conscripts spoke about compulsory military service in Egypt, drawing criticism from the media.
Al-Jazeera Managing Director Yasser Abu Hilalah denounced Hussein's arrest in remarks broadcast by the news channel.
"Mahmoud Hussein was on a visit to his country and was not working for Al-Jazeera at the time," he said, adding that the arrest "will not stop Al-Jazeera from its professional role".
"We will continue to cover Egypt and we don't succumb to pressure," he said.
Egypt provoked international condemnation in 2013 when it arrested three Al-Jazeera journalists, including a Canadian and an Australian, and sentenced them to jail on similar accusations.
They were later released.
Their arrest, months after the military overthrew Morsi who had been backed by Qatar, coincided with a massive crackdown on his supporters and the Muslim Brotherhood being blacklisted.