Al-Shalabi was apprehended along with a companion, about 90km north of the country’s capital Amman in the city of al-Malfraq. His companion was named as Omar Ghazi Bazay'a by local police.
The arrests come two days before the start of a trial at Jordan's state security court in connection with a plot to carry out attacks on the US embassy and other American targets in Jordan.
Al-Shalabi is among 10 Jordanians and three Saudi nationals accused of "conspiracy to carry out terrorist actions and of unauthorised possession of explosives", according to a charge sheet released in 13 August.
The suspects stand accused of plotting “military operations against the Americans” and planning to go to Afghanistan for jihad, following the 11 September 2001 attacks in the US.
Instead, they decided "to launch military operations in Jordan against the Americans", in particular against the embassy in Amman, the charges stated.
Six people, including a soldier and a policeman, were killed in the southern Jordanian city of Ma’an in November 2002 when the army launched a crackdown in the town aimed at arresting what it said were “armed bandits.”
The authorities accuse al-Shalabi of being the leader of a gang of armed brigands wanted in connection with a failed attempt to kill Ma’an police chief Ahmad al-Qadah in November 2002.