The Amsterdam station, Radio Ghurabaa, last week published what it said was an email Netherlands' National Coordinator for Counter-terrorism and Security Dick Shoof sent to its service provider, Versio, asking the hosting company to review whether the station was breaking its terms of service.
The email accused Radio Ghurabaa of spreading "jihadist ideology" and propaganda with the "aim of winning the hearts and minds of Muslims to a very radical ideological variant of Sunni Islam" and encouraging listeners to fight in Syria.
The station, it noted, broadcast lectures of Muslim scholar Anwar al-Awlaki, the American son of Yemeni parents who was accused by U.S. authorities of involvement in recruiting for al-Qaida before being killed in a 2011 drone strike in Yemen.
A spokesman for the security coordinator confirmed to Dutch broadcaster NRC Tuesday the email was genuine, adding while the anti-terror agency was "annoyed it had been leaked," it didn't dispute its content.
"It fits with our policy to alert Internet service providers if they are working with a website that is spreading such messages," the spokesman said.
Internet provider Versio was unavailable for comment Monday, NRC reported.
Radio Ghurabaa -- launched only weeks ago -- is seeking to induce Dutch youth to travel to Syria to perform holy war, describing it as an "obligation" while glorifying al-Qaida, Shoof asserted.
Listeners, it said, were told the "infidel West" is an "enemy of Islam" through the lectures of militant preachers such as al-Awlaki.
Belgian newspaper De Standaard reported the station features long hours of sermons and Arab male choirs without instrumental accompaniment, dotted with sound effects including explosions, swords being drawn from sheaths, marching soldiers and galloping horses.
A course on the life of the Prophet Muhammad, narrated in English by al-Awlaki, was also on the station's schedule.
Radio Ghurabaa said on its website it was being "demonized" by the anti-terror chief and denied issuing calls to jihad.
"Nowhere we have made such call, nor will we make such a call," the station's operators wrote. "It is an individual's choice as to whether or not to go -- we have nothing to do with it and would not want too."
While agreeing they have broadcast al-Awlaki's lectures, the station noted "these readings are not prohibited" and contended they were played to place them in a historical context and because they were in English.
"Is (Shoof) saying history classes in high school about World War II contain hate speech toward the Germans? No. Why are Islamic history lessons any different?"
Shoof told Dutch broadcaster BNR he would be willing to speak directly with Radio Ghurabaa and ask it "to engage with us and to see to what extent it is willing to adjust" its programming.
The station responded with another post on its website saying it had already sought a dialogue with Shoof but had been rebuffed because it was "standard operating procedure" to go through the Internet service providers in such cases.
"Anyway, Dick, we eagerly await your response," the post read. "Too bad this only came to mind afterwards."