Muraich joins a growing list of President Saied’s political opponents who are either in jail or facing prosecution.
Lotfi Muraich, leader of the Tunisian Republican Union party, who had announced his intention to run in the presidential elections scheduled for October, has been arrested on suspicion of money laundering.
The arrests were made on Wednesday in Tunisia’s northeastern Nabeul province, according to politicians and local media reports.
A court spokesman in Tunis said earlier this week that Muraich, one of President Kais Saied’s most prominent critics, was charged with money laundering and opening bank accounts abroad without the central bank’s permission.
Muraich’s arrest comes as the opposition, many of whose leaders are jailed, accuses Saied’s government of pressuring the judiciary to go after his rivals in upcoming elections and pave the way for him to win a second term.
Saied, elected president in 2019, has not formally announced his candidacy for the elections scheduled for October 6 but is widely expected to seek a second term. He said last year that he would not hand power over to so-called “unpatriots.”

The leader of the Free Constitutional Party and leading candidate, Abel Moussi, has been jailed since last year on charges of endangering public security.
Ms. Mussi’s party claimed she was jailed to exclude her from the presidential election, a charge denied by authorities.
The other candidates, including Safi Said, Nizar Shaari and Abd Elatif Mekki, face charges including fraud and money laundering.
A leading candidate, Mondair Znaidi, who lives in France, is also facing corruption charges.
The opposition argues that fair and credible elections cannot be held unless jailed politicians are released and the media is allowed to operate free from government pressure.
In 2021, President Saied seized nearly all power, dissolved parliament and began ruling by decree, a move the opposition called a coup.
He oversaw the drafting of a new constitution that would establish a presidential system and weaken parliament, to be approved in a 2022 referendum.
Saied said his measures were legal and necessary to end corruption that had long been widespread among the political elite.
Since last year, prominent opponents of the president have been detained on charges of conspiring against national security in a crackdown that has also included businessmen, media workers and politicians.