Documents obtained by German public radio and television broadcasters NDR and WDR along with German newspaper Süddeutsche Zeitung detail the complex bureaucratic system set up by the self-proclaimed "Islamic State" (IS) terrorist group.

The documents, which the reporters were allowed to peruse and copy in some cases, give extensive insight into the bureaucratic infrastructure IS has implemented in areas captured in Iraq and Syria. Among other things, they detail a complex health care and pension system, marriage benefits along with financial benefits to widows or wives of IS fighters captured in combat.

IS 'wants to be taken seriously'

The report released on Friday points to IS' seeing itself as more than just a militia: the jihad group fighting to install a caliphate in much of the Middle East sees itself as an actual state. Not only does the group have enough income - believed to be mostly from oil sales and ransom money - but it also has the bureaucratic infrastructure needed to run a caliphate.

Peter Neumann, an expert on terrorism and professor at King's College in London, told Süddeutsche the data show that IS "wants to be taken seriously as a state, and that it acts as a state."

The documents also list weapons purchases along with suicide missions and names of "martyrs" who have carried them out. It also details a budget of all nine IS provinces in Iraq and lists expenses for the self-declared caliph of IS, Abu Bakr al-Baghdadi.

Document seizure of 'great importance'

Iraq's vice interior minister, Adnan al-Assadi, said the seizure of the files was "of great importance. Al-Bilawi was a very important leader, [the IS'] number-two in command, and we profit from the seizure of the data and documents."

The Iraqi government said the data were found on over 160 memory sticks and hard drives seized in a raid on the hideout of one of IS' top guys, Abdul Rahman al-Bilawi, on June 5.

The government also said Germany's NDR, WDR and Süddeutsche Zeitung were the first foreign media outlets to gain access to the files, which were also passed on to US and European intelligence agencies.

Islamic State currency

On Thursday, the terrorist group announced plans to create its own currency. In a statement, the group said it would mint gold, silver and copper coins for use in its territories in Syria and Iraq. The currency would replace "the tyrannical currency system that was imposed on the Muslims and leads to their oppression."

War crimes on a 'massive scale'

A United Nations report released on Friday detailed atrocities committed by the terrorist group. According to the UN, Islamic State fighters are responsible for war crimes on a "massive scale" in northern Syria that include beheading, stoning and shooting civilians and captured fighters.