Members of the German, UK and Syrian media have acquired documents reportedly stolen from the personnel database of the terrorist organisation Islamic State.
Yle found information on five fighters who joined the organisation, although there may be more.
The leaked documents contain background information on some 2,000 Islamic State members. The Finnish Security Intelligence Service Supo has confirmed that the material appears to be genuine.
Yle's investigation has so far uncovered the names of five individuals who left Finland to join in the terrorist group’s ranks. Examination of the material continues, however, and more names linked to Finland may yet surface.
Five individuals from Finland
The data indicate that the five men in question travelled to join Islamic State in the spring and summer of 2014, two years ago.
One of the five is a native of Finland. Two of the others have Finnish citizenship and the remaining two do not.
Originally from Somalia, one individual is a Finnish citizen who lived in the southern region of Pirkanmaa. Yle research has determined that he is still at large in an Islamic State location and that he has sought to radicalise others to join IS.
Another is a Finnish-born man, also from Pirkanmaa. He travelled to join Islamic State together with the Somali-born man in June 2014.
The third is a Bangladesh native and resident of the capital region who registered as a member of the Islamic State in June 2014. and maintained close contact with the Somali-born man. He is known to be still at large.
A second Bangladeshi man also hailed from the capital region. Ten years older than his compatriot, he travelled to join the Islamic State in July 2014 and was recruited by the same Somali-born man.
Finally, a Kurdish man who resided in the capital region city of Espoo. Sadiq Qadir Karim was also the alleged leader of the Finnish cell of the Rawti Shax terrorist organisation. Italian police report that he was killed in Iraq in December 2014. He registered as an Islamic State member in March 2014.
Still assumed active in IS
Two of the men, one originally from Somalia and another from Bangladesh, are part of a Finnish jihadist network that Yle has reported on earlier.
According to the documents in Yle's possession, both men are still alive and at large in Islamic State-controlled areas.
A third individual is the alleged leader of the Finnish faction of the Rawti Shax terrorist organisation, a European offshoot of the Iraqi Kurdish jihadist network Ansar al-Islam. He made the news last November when Italian police carried out an extensive crackdown on terrorist operations throughout Europe.
The final two are a Finnish-born man from the southern region of Pirkanmaa and a second Bangladesh native who resided in Helsinki. Yle was unable to confirm the status or whereabouts of these IS recruits.
No volunteers for suicide attacks
The leaked documents are standardised registration forms that fresh Islamic State recruits were asked to complete as part of their initial membership interview.
The forms indicated that none of the five men had any previous jihadist experience. No one registered as a potential volunteer for a suicide attack, although each of the five indicated a desire to fight for the terrorist group.
All of the five relinquished their passports to the so-called Islamic State, and the majority also surrendered their phones and computers.
The documents indicated that four of the five men on the list were connected. Each indicated the same names as references on their registration forms, arrived in Syria at around the same time and entered the country via the same Jarabulus border crossing.
The central figure of the group appears to be a young man in his twenties originally from Somalia, who left his home in southern Pirkanmaa to travel to Syria in early June 2014.
Yle has access to previous information indicating that he was in regular contact with plenty of other men and women who left for Syria before his departure.
Finnish intelligence not commenting on names yet
The German public broadcasting companies NDR and WDR joined with the national newspaper Süddeutsche Zeitung to break the news of the stolen personnel register two weeks ago.
That same week the British news service Sky News reported that it had received 22,000 documents from a former IS fighter who said he had become disillusioned with the group's leadership and stole a memory stick.
The Syrian online publication Zaman Al Wasl also published some of the leaked information. The documents were later found to include several duplicates, however, and actually profiled far fewer individuals.
Investigative journalists in Germany estimate that fewer than 2,000 names are included in the material, a number that may fall as the documents are examined further.
The German Federal Bureau of Investigation is acting on the assumption that the leaked documents are authentic. The Finnish Security Intelligence Service Supo has stated that it does not have any reason to suspect that the material published to date is not genuine.
Supo said it is not commenting on the names found on the list at this point, however, as it is still in the process of evaluating the material with its international partners.
Finnish authorities have confirmed that over 70 persons have travelled to the conflict regions of Syria and Iraq in recent years. Supo has admitted that the true number is likely larger, and efforts to correctly identify all of the radicalised individuals continue.
Many hoped that this rare leak of Islamic State membership information could provide some help in tracking down the IS terrorists.
If the documents fail to reveal more names with Finnish connections, they are lilkely to be of little benefit to anti-terrorism authorities.