A German rapper who became a brutal poster boy for ISIS was married to a woman who was spying on him for the FBI, according to a new report.

The report claims that Denis Cuspert - who was also known as "Deso Dogg" and who now calls himself Abu Talha al-Amani - married a woman in Syria.

German and American intelligence sources confirmed that she transmitted critical information to the FBI, including details of top secret ISIS operations.

The unidentified woman left Syria when her handlers told her she was no longer safe. She is believed to now be in the U.S.

FoxNews.com previously reported that Cuspert, who was seen in an ISIS propaganda video in November hoisting the severed head of an "enemy of Islamic State," serves as a recruiter of German-speaking Islamists.

Numerous videos feature Cuspert encouraging Germans to embrace jihad in Syria and to "bring jihad to Germany."

German intelligence officials estimate that 500 German Muslims have traveled to Iraq and Syria, and roughly 150 radical Islamic fighters have returned to Germany.

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FoxNews.com reported:

Cuspert may have been ripe for the tried-and-true espionage technique. According to Bild, he was a womanizer in Germany, where he fathered three children with three women, including one who he dumped before embarking on his terrorist career. Cuspert arrived in Syria in 2013 from a so-called German jihadi colony in Egypt. It was not clear when he "married" the spy, but Bild reported that she informed her U.S.  handler via secret methods on regular basis about Islamic State activities. It was unclear how she transmitted the information to her handler.

The timing of the “honey trap” revelations coincided with last week's designation by the U.S. of Cuspert as a “global terrorist.”

"Denis Cuspert stands in the focus of security circles because of his essential role for Islamic State,” a German law enforcement official told FoxNews.com. “He is propagandist of IS."

The material gleaned by the spy served as the basis for the U.S. State Department's designation, according to Bild, which reported that Germany’s top prosecutorial office benefited from the seduction mission. Germany’s federal prosecutor has used the material to launch an investigation into Cuspert’s Islamic State activities.

FBI officials did not return requests for comment.

Watch the clip from "Fox and Friends" above.

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