Shaikh Abu Muhammad al-Maqdisi was arrested earlier this month and is being held as part of an investigation on charges of conspiracy, a judicial source said on Thursday.
"Abu Muhammad al-Maqdisi is being held for a renewable 15-day period on the orders of the state prosecutor as part of an investigation on charges of conspiracy to carry out subversive acts," the source said.
No charges yet
At the end of the investigation, the state security court will decide whether or not he will be formally charged and prosecuted, the source added.
Al-Maqdisi, a Jordanian of Palestinian origin, whose real name is Issam al-Barqawi, was rearrested by the Jordanian authorities earlier this month a week after being released from jail.
He was set free from custody on 28 June, six months after being acquitted of plotting attacks against the US embassy and other targets, for lack of evidence.
"After his release from jail, we received information indicating that he made contact with terrorist groups outside Jordan," Deputy Prime Minister Marwan Moasher said earlier this month.
Al-Maqdisi gave several interviews to the media after his release from jail in June, including one to Aljazeera in which he expressed "reservations" about attacks carried out in Iraq by al-Zarqawi's followers.