Turkish authorities have detained Istanbul Mayor Ekrem Imamoglu, a key rival to President Recep Tayyip Erdogan, as part of corruption and terror investigations, according to state broadcaster TRT, citing the Istanbul Prosecutor’s Office.

Turkey detained Istanbul Mayor Ekrem Imamoglu on Wednesday on charges such as graft and aiding a terrorist group, a step the main opposition party criticised as a "coup attempt against the next president".

Istanbul's powerful mayor Ekrem Imamoglu is President Recep Tayyip Erdogan's biggest political rival who has faced a growing barrage of legal challenges aimed at stopping his bid to win Turkey's