The German rapper who became a grisly poster boy for ISIS fell for the oldest trick in the book, according to a report that said the woman "Deso Dogg" thought was his wife was an FBI spy.

The spy transmitted critical information about the rapper, who was born Denis Cuspert and now goes by Abu Talha al-Alman, as well as his Islamic State colleagues before slipping into Turkey, where she was arrested and then turned over to the U.S., according to the German newspaper Bild. The paper cited German and American intelligence sources as confirming the operation.

“We were already a long time in the bedrooms of the terrorists.”

- German intelligence official

“We were already a long time in the bedrooms of the terrorists,” Bild quoted one security official as saying.

The unidentified woman left Syria as Islamic State began a hunt for infiltrators, and her handlers told her it was no longer safe. She is believed to now be in the U.S.

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 “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. reported last week that Cuspert, who was seen in an ISIS propaganda video in November hoisting the severed head of an "enemy of Islamic State," was deeply involved in the radical German Salafist scene before his departure for the Middle East. According to Germany’s domestic intelligence agency, there are nearly 7,000 active Salafists, who adhere to a strict, hard-core anti-Western interpretation of Sunni Islam.

Cuspert, the son of a Ghanian father and a German mother, serves as a recruiter of German-speaking Islamists. Numerous YouTube videos show him encouraging Germans to embrace jihad in Syria and to “bring jihad to Germany.”

The most recent German intelligence data estimates 500 German Muslims have traveled to the Iraqi and Syrian war theaters. Roughly 150 radical Islamic fighters are back in Germany, posing an enormous challenge for the country’s taxed counter-terrorism officials.

Benjamin Weinthal reports on human rights in the Middle East and is a fellow at the Foundation for Defense of Democracies. Follow him on Twitter @BenWeinthal