At least 20 peoplehave been detained on Monday over their alleged links to Turkey’s Gülen movement, the Diken news website reported.

Ali Demir, the former head of Turkey’s Student Selection and Placement Center (ÖSYM), was among suspects detained by police as part of an investigation carried out by the Ankara Chief Public Prosecutor’s Office.

Ali Demir was appointed president of the ÖSYM in 2010 by then-Prime Minister Recep Tayyip Erdoğan’s government, and a year after that he was accused of rigging student exams.

He was removed from office in 2015 by the government.

Turkey accuses the Gülen movement of orchestrating a 2016 coup attempt, although the movement denies any involvement.

Some critics claimed the Gülen movement was cheating in the exams, as it had been successful in the education sector, dominating the university entrance exams and enrolling students in colleges affiliated with the movement.

Only one incident of rigging the central exam has been the subject of investigation and trial.