The German government has obtained a set of documents from the Islamic State group that it says will help it identify and discipline nationals who return home after joining the extremists in the Middle East. Interior Minister Thomas de Maiziere confirmed Tuesday the federal criminal police planned to analyze the paperwork and use it to get "speedier, clearer investigations and stricter prison sentences," Deutsche Presse-Agentur reported.

The classified documents were multiple-question quizzes of sorts for people who left Germany for Syria and Iraq, where the terrorist organization, aka ISIS, is headquartered. Upon arrival, new ISIS members told the organization facts like their names, addresses, education levels and whether they had experience with jihad, according to Tagesschau. They also indicated whether they were willing to serve as suicide bombers.

De Maiziere said the materials help clarify "the underlying structures of this terrorist organization." 

The paperwork was revealed Monday in a report from radio broadcasters NDR and WDR, and newspaper Süddeutsche Zeitung. The documents were thought to be authentic — and valuable for investigators tracking citizens who join ISIS and return to Germany, Deutsche Welle reported.

As of last June, German police chief Hans-Georg Maassen said about 700 Germans had gone to Syria and Iraq to fight with ISIS. Reuters reported the number of ISIS supporters within Germany was about 7,500. “The threat is becoming increasingly complex,” Maassen told reporters at the time.

More than 100 Germans have died in combat for ISIS. One of the most high-profile casualties was Denis "Deso Dogg" Cuspert, a rapper-turned-propaganda producer who had joined the extremist organization in 2012. Deutsche Welle called Cuspert a "minor celebrity" who, after becoming an ISIS member, starred in a series of videos vowing to attack Germany and other countries.

Cuspert was killed this past October in an American airstrike in Syria, according to CNN.