Anti-terror units of the National Police launched operations in 20 cities on Tuesday to detain 45 suspects linked to the controversial Gülen Movement who were involved in the illegal wiretapping of hundreds of people.

A total of 30 suspects, all of them low-ranking police officers and former police chiefs, were detained in the raids ordered by the Chief Prosecutor's Office in Ankara as part of an inquiry into the Gülenist Terror Organization / Parallel State Structure (FETÖ / PDY). FETÖ / PDY is the name prosecutors have given to refer to followers of the Gülen Movement accused of attempting to overthrow the government.

The Gülen Movement, led by U.S.-based retired preacher Fethullah Gülen, runs a network of schools and companies in Turkey as well as across the world. The organization calls itself the Hizmet (Service) Movement, and claims its activities are solely focused on educational services. However, the movement, which originally began as a religious organization, has morphed into a group that is now accused of placing infiltrators within the judiciary, police and state institutions in its attempts to topple the government through a string of criminal inquiries launched by Gülenist prosecutors, judges and police chiefs.

Suspects detained in yesterday's operations are charged with the "illegal wiretapping" of 432 people. Previous investigations revealed that Gülen-linked police officers allegedly attributed false names to the wiretapped victims and issued documents classifying those they targeted as members of an imaginary terrorist organization that the FETÖ / PDY claimed justified the wiretapping.

Detainees reportedly wiretapped politicians from the ruling Justice and Development Party (AK Party) as well as opposition parties, military officers, bureaucrats, law enforcement officials, high-ranking judiciary members, businesspeople and journalists, according to a report by the state-run Anadolu Agency (AA).

One of the highest-ranking names listed among the detainees is Sami Uslu, the former police chief of İzmir – a western city of Turkey where Gülen resided for years and where the Gülenists are believed to have a wide clout within the city's business circles. Muharrem Durmaz, the former police chief of the eastern city of Muş, and Hami Güney, a deputy police officer from the intelligence department of the Turkish National Police in the capital, Ankara, are among the suspects who remain at large.

The Gülen Movement is already entangled in a series of police operations and lawsuits for alleged fraud, illegal wiretapping, blackmail and plots to overthrow the government. Its high-ranking members have already fled overseas since police operations began in 2014.