Turkey's state-run agency says prosecutors have dropped a corruption investigation that forced three ministers to resign and rocked the Turkish government earlier in the year.

The Anadolu Agency said late Friday prosecutors in Istanbul ruled there were no grounds for legal action against 53 suspects, including two former ministers' sons. Prosecutors also dismissed a separate corruption case in September.

The government had rejected the corruption allegations, insisting the probe was orchestrated by followers of an influential U.S.-based Muslim cleric that it claims aimed to topple the government.

Prosecutors and police investigating the probe were replaced and dozens of police officers have since been detained across Turkey on suspicion of illegal wiretaps.

Recep Tayyip Erdogan, who was prime minister at the time, won elections in August to become president.