The 19-year-old son of a former senior counter-terrorism official in Turkey was arrested over coup charges after his father implicated links between Turkish government and the terrorist Islamic State of Iraq and the Levant (ISIL).

Ahmet Yayla, who served as the chief of the Counter-Terrorism and Operations Division of Turkish National Police between 2010 and 2012 and as the Chief of the Public Order and Crime Prevention Division afterwards, resigned from civil service after he reportedly witnessed the government’s support to ISIL militants, in 2014.

Yavuz Selim Yayla, a 19-year-old college student and the son of the former police officer was arrested on coup charges charges after his father argued in his interviews and a recently-published book that President Recep Tayyip Erdoğan as well as the high-level government officials have been deliberately backing the ISIL militants.

Yayla, in his book titled “ISIS Defectors: Inside Stories of the Terrorist Caliphate”, quotes an ISIL militant as claiming that Turkish government sent arms, weaponries, and explosives to ISIL territories; and let militants freely cross Turkish borders in between 2014 and 2015. Yayla’s book hit the shelves on July 1.

The son Yayla was arrested over his alleged links to the coup plotters after a judge found out that his father was among thousands others who have had their passports cancelled in anti-coup probes, in late July.

The whistleblower told independent journalist Nafeez Ahmed that Turkish authorities had cancelled the passports of him and his family members in July 2016, after he wrote an article highlighting evidence of Erdogan’s support for terrorism.

Turkey has detained more than 40,000 people and arrested 24,000 over alleged links the July 15 coup attempt. Critics have lambasted the government for a massive purge it is carrying out that violates the principle of individual criminal responsibility.

Detention of family members in the absence of actual suspects is nothing new, either. Wife of Bülent Korucu, Turkish journalist wanted in anti-coup probes, were arrested by police who told the couple’s son that the mother would be held hostage until the father surrenders, in late July.

Both the mother and father-in-law of Adil Öksüz, one of the prime suspects wanted for his alleged role in an attempted coup, were arrested in August.