Slah Ben Ali was arrested during the weekend by authorities in Sousse, south of the Tunisia capital, al-Jazeera reports. The interior ministry provided few details about the arrest, however.
A court in Tunisia announced March 9 it decided to dissolve the Rally for Constitutional Democracy of the former president and liquidate its assets.
The RCD was accused of violating the country's constitution by establishing a "totalitarian regime."
The interim Tunisian government suspended the official activity of the RCD after the former president fled the country to Saudi Arabia in January.
Tunisian authorities nominated Beji Caid Sebsi as the new prime minister after Mohamed Ghannouchi bowed to protesters' demands and resigned as prime minister in February. Elections are set tentatively for July.
A protest suicide in December sparked the so-called Jasmine Revolution that brought an end to the Ben Ali regime after more than 23 years in power.