Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

MAINZ, Germany — A former German rapper known as "Deso Dogg" has been declared an international terrorist over alleged ties to ISIS and added to the U.S. terror blacklist.

According to the State Department, 39-year-old Denis Cuspert — who now goes by the name Abu Talha al-Almani — joined the group now known as ISIS in 2012, has pledged allegiance to its leader and appeared in numerous videos on behalf of the terror organization. In the most recent video, which was released in November, Cuspert "appears holding a severed head he claims belongs to a man executed for opposing" ISIS, the State Department said in a statement.

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

The State Department said Cuspert is "emblematic of the type of foreign recruit" ISIS seeks, has been a "willing pitchman" for the organization's "atrocities" and as such been officially designated as a “foreign terrorist fighter and operative" for the group.

Denis Cuspert — who is also known as Deso Dogg — poses in Berlin, Germany, in 2005. DPA via AP Images

Cuspert — who the State Department said is wanted by the German government on suspicion of terrorism activities — has long been on the radar of intelligence officials back home.

Last September, German intelligence officials put together a 25-page analysis on the Berlin native’s radicalization process. It said that Cuspert — who as Deso Dogg rapped "welcome to my world full of hate and blood" in a 2007 music video — is believed to have been radicalized in Germany's Salafist scene and quickly gained popularity as a radical preacher who tried to recruit followers for ISIS. Cuspert "in a few years developed into a well-known German-speaking demagogue of the armed Jihad," the report said.

According to Germany’s Die Welt am Sonntag newspaper, Germany’s Federal Prosecutor is investigating whether Cuspert and another German national suspected of fighting for ISIS could be charged with war crimes.

Germany's Federal Prosecutor's Office declined to comment on that report, saying only that it is "studying the conflict in Syria and Iraq under all legal aspects within its responsibility.”

There have been several rumors suggesting that Cuspert was wounded or dead in Syria. The State Department designation would indicate he is believed to be still alive.