A new documentary series prepared by state-run news channel TRT World on the PKK terrorist group's presence in Europe exposes how far its crime network reaches on the continent. The documentary, "Hidden Threat," aired on TRT World Wednesday night.

For the documentary, a group of investigative journalists from the news channel visited scores of European countries, including Germany, the U.K., Belgium, Sweden, the Netherlands and Denmark to explore the PKK's criminal network, which has been largely ignored by police and intelligence units in those countries.

For the documentary, the investigation team studied pages of official intelligence reports and cables, and interviewed senior police officers, intelligence experts, state prosecutors and even drug dealers.

It focused on the PKK's various illegal activities, in particular the human smuggling and drug networks the terrorist group has engaged in since the ‘90s. The documentary also reveals in detail how Kurdish businessmen in European countries are forced to pay the PKK, and how students in schools are recruited by the terrorist group. The documentary suggested that the PKK extorts "almost $31 million every year from Kurdish businesspeople" in Europe.

After the exposure of the PKK's extensive crime network, TRT World journalists requested interviews from European authorities and institutions on the issue; however, the responses were negative, or the requests were ignored.

Last year, a report from the European Union's law enforcement agency EUROPOL revealed that Belgium, France, Germany, Italy, Romania and Switzerland are countries where the PKK openly conducts propaganda and fundraising activities, according to the publication "The European Union Terrorism Situation and Trend Report 2017."

"Belgium, France, German, Italy, Romania and Switzerland reported that the PKK has continued its fundraising, propaganda and recruitment activities," the report said, adding that the terrorist group has a powerful organization and support in France, Italy and Switzerland, the report revealed.

Although the PKK is listed as a terrorist organization by the EU, authorities have been reluctant to take strong measures against the funding, propaganda and recruitment activities of the group, despite repeated warnings from Turkey.

Interior Ministry spokeswoman Sonja Kock confirmed in the documentary that the PKK is a threat to Europe and Germany, adding, "Our security services prioritize surveillance of the PKK as violent acts are repeatedly carried out in Germany."

In the documentary, Gordian Meyer-Plath, president of the State Offices for the Protection of the Constitution (LfV) in Sachsen, confirmed that PKK recruitment included teenagers in Germany. He added that the terrorist group has youth and women's organizations as well as other subgroups in an effort to "camouflage or conceal that these are PKK-run organizations."

Another report released last year by the domestic intelligence service of Germany, which was presented as "the largest PKK stronghold in Europe" in the TRT World documentary, said the PKK terror group collects 25 million euros annually in donations from across Europe.

The terrorist group collected more than 13 million euros in Germany alone from September 2015 to early 2016, according to Germany's Federal Office for the Protection of the Constitution (BfV).