Prosecutor Muammer Akkaş, known for his work on sensitive cases like the Ergenekon coup plot and the murder of the Turkish Armenian journalist Hrant Dink, is leading the investigation, which is seen as the second round of a graft probe that has shaken Turkey's political establishment.
Early media reports claimed that the investigation concerns al-Qaeda operations in Turkey as well as business deals in which deputies and public officials are involved.
Akkaş gave the order to detain the suspects to the İstanbul police in the afternoon. The police, however, did not immediately comply; the İstanbul Police Department did not assign a team to carry out the mission. Later that day all the department's police chiefs were summoned to a meeting at the department's headquarters.
In an overnight change to police procedure for judicial investigations last week, the government stifled prosecutorial independence by requiring police officers to report to their superiors in all investigations. In the current probe into corruption and bribery, that would have forced the police to inform the interior minister that they were investigating his son.
The government has also removed or reassigned hundreds of police officers involved in the investigation.
The İstanbul Chief Public Prosecutor's Office has launched an investigation into the police officers who refused to carry out the detention orders. Turkish media have reported that the probe involves allegations against İstanbul Governor Hüseyin Avni Mutlu, Selami Altınok and the chief of the financial crimes unit, Hakan Sıralı, of insubordination, violation of the confidentiality of an investigation and aiding and abetting a criminal.
Last week the prosecution summoned the chief of the İstanbul Police Department's intelligence unit, Ahmet Arıbaş, to testify about allegations that he had leaked documents about the corruption investigation. The department's newly appointed head Selami Altınok, however, turned down the court's request and declined to send the officer.
Around $100 billion in bribes are said to be involved in the case.
Soon after the story surfaced, Turkish media outlets claiming to have sources close to the case said that the following people were named in the detention order: Yasin al-Qadi, listed as a terrorist by the US; Üsame Kutup; Orhan Cemal Kalyoncu; Turkish State Railways (TCDD) General Director Süleyman Karaman; İstanbul Metropolitan Municipality Secretary-General Adem Baştürk; the prime minister's son, Bilal Erdoğan; as well as businessmen Mustafa Latif Topbaş, Abdullah Tivnikli and Cengiz Aktürk. None of these names had been confirmed at press time.