Turkish police have arrested “Abu Hanzala,” code-named “Halis Bayancuk,” as part of an ongoing crackdown on the Islamic State of Iraq and the Levant (ISIL) operating in the northwestern province of Sakarya.

“The latest detention on May 30 was carried out as a part of an investigation launched by the Sakarya Chief Public Prosecutor’s Office,” the Turkish Hurriyet Daily News reported on Wednesday.

Bayancuk and his wife were arrested in 2015 after police raided their home and seized a number of ISIL-linked documents, both digital and non-digital, but he was released in March 2016, according to the report. Bayancuk was detained again in March 2017 after he threatened personnel of the Istanbul Governor’s Office via a video broadcast online, and had also been arrested in 2011 and 2014 for “being a member of al-Qaeda.” He was released both times after serving a couple of months in jail, the Hurriyet Daily News reported.

In March, Breitbart News reported that Turkey has been accused of playing a “double game” on the Islamic State in Syria, with President Erdoğan accused of helping ISIL in its fight against Kurdish rebels and Syria’s President Bashar al-Assad.

An ex-Islamic State militant told Newsweek in 2014 that the Islamic State saw Turkey as its ally, saying, “ISIS commanders told us to fear nothing at all because there was full cooperation with the Turks.” The man, called “Sherko Omer” for his safety, said, “ISIS and Turkey cooperate together on the ground on the basis that they have a common enemy to destroy, the Kurds.”

Last year, Al-Monitor reported:

The Cumhuriyet daily’s editor-in-chief Can Dundar and Ankara representative Erdem Gul landed behind bars Nov. 27 for reporting that Turkish intelligence shipped weapons to radical Islamists in Syria. Though they were released three months later, they eventually received jail terms for revealing state secrets.

Ahmet S. Yayla, deputy director of the International Center for the Study of Violent Extremism (ICSVE) and adjunct professor of Criminology, Law and Society at George Mason University, wrote about Bayancuk in 2016. Below are excerpts from his account of the terrorist and his numerous arrests and releases:

After Halis Bayancuk’s father’s arrest in 2005, Halis was sent to Egypt with other Turkish Hezbollah members for ideological education with support from Turkish Hezbollah members residing in Germany. When Halis returned to Turkey in 2008, he was already an al-Qaeda member and started to preach for al-Qaeda, especially among his father’s old connections, converting several TH members to al-Qaeda. Halis was then arrested by the Turkish National Police for sending children around the age of fifteen to nineteen to receive training at al-Qaeda camps in Afghanistan and for being among the perpetrators of the al-Qaeda synagogue bombings in Istanbul in 2008.

He was released on May 15, 2009 due to lack of evidence. Halis did not halt his terrorist activities and as the police kept following him, it was realized that an al-Qaeda cell under the control of Halis was about to carry out a serious bombing attack in Turkey which would attract worldwide attention. As a result, Halis and fifty other al-Qaeda members were arrested in 2011. However, Halis was again released from prison on January 24, 2013 again due to lack of enough evidence.

When Halis left prison again on November 9, 2014, he established ties with newly emerging ISIS. Halis was never shy about the support he was extending to ISIS and he started to openly preach about why ISIS needed to be supported. In one of his sermons just weeks after he was released from prison on December 21, 2014, Halis clearly and in detail explained in a video … why Muslims should and must support ISIS.”

With the opposition pressuring the Erdogan government about the open and undisturbed activities of ISIS as ISIS attacks have been carried out around the country including the Suruc suicide attack killing tens of people, the police had to rearrest Halis Bayancuk. They did so on July 24, 2015 with the charges of being the leader of ISIS in Turkey and facilitating two French women to go to Gaziantep from Istanbul and enable their journey onward to Syria to join ISIS.

However, unexpectedly, Halis and all 95 of the other suspects in the main ISIS case were suddenly released on March 24, 2016 during the fourth hearing. The details of the trials were discussed in the media as the suspects were inexplicably released.