Turkey's main opposition Republican People's Party (CHP) referred Murat Hazinedar, the mayor of Istanbul's Beşiktaş district, to its disciplinary board on Thursday.
Party spokesperson Selin Sayek Böke said that the High Disciplinary Board will review allegations about Hazinedar that he has acted against party rules.
Hazinedar was banned from travelling abroad upon Istanbul Chief Public Prosecutor's request on Aug. 6 as part of post-July 15 coup attempt investigations.
Media reports suggested that several lawmakers from the party - including party caucus members Aykut Erdoğdu, İlhan Cihaner and Mehmet Ali Çelebi - have accused Hazinedar of having ties with the Gülenist Terror Group (FETÖ). Hazinedar rejects the accusations.
Hazinedar was elected to the mayoral post in the March 2014 local elections, in which the CHP won over 76 percent of the votes in the district that serves as one of Istanbul's main commerce, culture and transport hubs.