Ko Wen-je, the former mayor of Taipei and leader of the Taiwan People’s Party (TPP) was arrested in connection with allegations of corruption linked to Taipei’s Core Pacific City redevelopment project, which took place during Ko’s 2014-2022 tenure as mayor, his party said Saturday.

Ko, who garnered significant support as a third-party candidate in Taiwan’s recent presidential election, refused to continue a marathon overnight interrogation session, prompting prosecutors to detain him. The Taipei District Prosecutor’s Office cited concerns of potential collusion as the reason for the arrest.

Under Taiwanese law, prosecutors must seek court approval to detain a suspect within 24 hours of interrogation. Ko has since requested a judicial review of the arrest decision.

The corruption scandal centers on an alleged illicit increase in the floor area ratio (FAR) of the Core Pacific City project, a move that reportedly benefitted property developers by expanding the project’s profitability. Investigators have named Ko and several former Taipei City officials as suspects.

Ko’s arrest comes amid a broader wave of investigations into Taiwanese politicians for corruption and misconduct. The TPP, in a statement, called for the court to scrutinize the legality of the arrest and defend Ko’s rights.

Ko, a former trauma surgeon, was a surprise contender in the January presidential race, securing nearly 27 percent of the vote.