Germany has confirmed it has the documents that reveal identities of at least 22,000 members of extremist group Islamic State of Iraq and Syria (ISIS). Multiple residents of the U.K. and the U.S. have also been found to be part of the terrorist organisation.

Sky News said that it had received a similar document revealing identities of 22,000 recruits, while Zaman Al-Wasl, a Syria-based independent news site, said that it had 1,736 names. The recruits' names, addresses, blood type, profession and other personal details are mentioned in the documents, the two news sites said.

German Interior Minister Thomas de Maizière confirmed the documents as real and that the information would help with "speedier, clearer investigations and stricter prison sentences." The German Federal Police have also confirmed that they have the documents, reports the Guardian.

Identities of Jihadis from at least 51 countries, including the U.K., the U.S., France, Canada have been revealed, reports Sky News. Some jihadis were previously known to the authorities, but identities of previously unknown jihadis in Canada, the U.K., Europe, the U.S., Middle East and Africa have been leaked.

Saudi Arabians make up 25 percent of ISIS members, while Saudis, Moroccons, Egyptians and Tunisians together constitute two-thirds of their manpower. Among foreign fighters, Turkish people are reportedly the most in number, followed by French. Syrians, however, make up 1.7 percent, while Iraqis 1.2 percent in the terrorist network, according to Zaman Al-Wasl.

A file named "Martyrs" lists names of people who are willing to be suicide bombers for the group.

Sky News claims that the file was given to them by a former Free Syrian Army member who later joined the Islamic State group. The man quit the group after being disillusioned by the organisation as it was taken over by former members of the Iraqi Baath party of Saddam Hussein.

Zaman Al-Wasl said that the document was organised and written by General Administration of Borders and the ISIS commission, which is responsible for maintaining data about the members in the Islamist group.

The form consists of 23 questions to be filled by recruits, who write about their willingness to become a fighter or a suicide bomber.