The confidential files related to the Military Reaction Force (MRF), an elite unit in Northern Ireland that allegedly shot unarmed civilians during the Troubles in the early 1970s.
“An inexperienced researcher allegedly downloaded a cache of material from an online dropbox service on to a USB stick and handed it to a third party,” the Independent reports.
Initially, the data was believed only to pertain to BBC’s investigation into alleged questionable practices at the London Borough of Tower Hamlets.
The researcher leaked the file to the Tower Hamlets mayor’s office because she did not believe the April documentary was balanced.
But the material also included information on former soldiers from the controversial MRF, because of a deletion error.
The undeleted data contained confidential information relating to “Britain’s Secret Terror Force”, a highly sensitive previous BBC program, which was shown last November.
“It is understood that at least one former serviceman from the elite unit has had his identity compromised,” according to the Independent.
Names and details of other senior military figures – in addition to those who served with the MRF – were also stored in the file.
"The woman who leaked it was a broadcast journalism student who worked with the production company for a short period," the Huffington Post reports. Five days -- according to the Independent.
It is believed the file has since been destroyed.