Imamoglu “was arrested by the criminal court to which he was referred to within the scope of the ‘corruption’ investigation” against the city’s municipality, the state-run Anadolu Agency reported.
The court is set to rule on a second case of “terror-related” allegations later on Sunday.
Imamoglu, from the main opposition Republican People’s Party (CHP), is sitting President Recep Tayyip Erdogan’s biggest political rival. His detention on Wednesday came days before the party was set to pick him as their presidential candidate for the 2028 election.
“No despair! Keep fighting!” the CHP wrote on X.
On Wednesday, Turkish police raided Imamoglu’s house and detained him for “various crimes” including aiding the Kurdistan Workers’ Party (PKK). More than 100 suspects were detained in the operation.
Imamoglu’s arrest also came as the CHP moved ahead with a primary to elect Imamoglu as its candidate against Erdogan in 2028. Polls were opened to everyone, not just CHP members, as the party sought to bolster support for their arrested mayor.
His detention sparked protests in Istanbul and many Turkish provinces, with demonstrators supporting him clashing with riot police. At least 323 people were arrested after mass protests on Saturday, according to Interior Minister Ali Yerlikaya.
The pro-Kurdish Peoples’ Equality and Democracy Party (DEM Party) condemned the arrest of Imamoglu, saying it was made on “fabricated grounds and politically motivated grounds.”
“There has been political interference in the will of millions of citizens. This mentality, which has been increasing tension in Turkey for decades and dragging society into unrest, continues to cause the greatest harm to Turkey’s internal peace,” DEM Party co-chair Tuncer Bakirhan said on X.
Imamoglu’s potential presidential candidacy took a heavy hit on Tuesday when a Turkish university revoked his university diploma, citing irregularities. If the decision is ratified, Imamoglu could be blocked from running in the 2028 presidential vote.