A judge ordered the detention of Tunisian media mogul Nabil Karoui on Thursday on suspicion of financial corruption, a spokesman for the judicial court said.
Mr Karoui is the leader of the Heart of Tunisia party, the second-largest party in parliament, and has previously run for president. His party is one of three that support the technocratic government in parliament.
Mr Karoui's aides and party officials were not immediately available to comment.
TAP state news agency said Mr Karoui was to face charges of tax evasion and money laundering.
Mr Karoui was arrested in August 2019 but released a few months later on October 9, in the middle of the election, although investigations into his case continued.
Last year, Mr Karoui said he was confident of his innocence and that his political opponents, specifically the Islamist Ennahda Party, were behind his imprisonment. Mr Karoui is now an Ennahda ally in parliament.