Tayyip Erdogan’s main political opponents have faced an unprecedented crackdown that has seen more than 500 detained in just nine months, according to a Reuters review of a sprawling investigation that has accelerated dramatically in recent days. Turkey’s president says the probe tackles what he calls a corrupt network that is like “an octopus whose arms stretch to other parts of Turkey and abroad.” The investigation, which began in Istanbul but has spread across the country, has targetted only municipalities run by the main opposition Republican People’s Party, or CHP, the party of modern Turkey’s secularist founder Mustafa Kemal Ataturk. The CHP denies the corruption allegations and calls them a naked attempt to eliminate a democratic alternative for Turks, a charge the government refutes. The crackdown tightens Erdogan’s two-decade grip on power at a time that Turkey’s influence in the Middle East and Europe has grown. For this reason, diplomats and analysts say, it has garnered only muted criticism from Western allies as a threat to democracy even as street protests erupted in the spring. According to the review of legal filings and state disclosures, 14 elected CHP mayors, including Istanbul’s Ekrem Imamoglu – Erdogan’s main rival – and more than 200 party members or local officials have been jailed pending trial. Not since a series of coups in the 1960s, 1970s and 1980s have such high-profile political leaders been removed from office on the basis of as yet unpublished evidence, which suspects’ lawyers dismiss as fabricated.

Full analysis : Turkey detains hundreds of Erdogan opponents in pursuit of ‘octopus’ of corruption.