An estimated 3-12 million victims of Soviet repression were imprisoned in the gulag network of prisons and forced labor camps in the former Soviet Union. Registration records kept by the Museum of the History of the Gulag, now threatened with destruction, include the permanent records of those killed, as well as archival files detailing those who survived the gulag and when they were released.

Russian officials are reportedly destroying the records of gulag prisoners under a secret order passed in 2014, Russian media have reported.

A 2014 inter-agency order labeled “for internal use” instructs files to be destroyed once the former prisoner reaches the age of 80, Russia’s Kommersant business daily cited a regional police official as saying Friday.

“This information is forgotten once it’s destroyed,” gulag historian Sergei Prudovsky, who revealed the practice, was quoted as saying.

The internal order was signed by 11 Russian state agencies, including the KGB’s successor agency, the FSB, the Foreign Intelligence Service (SVR), the Interior Ministry, Justice Ministry, and the General Prosecutor’s Office, Kommersant reported.

Gulag Museum director Roman Romanov asked presidential Human Rights Council head Mikhail Fedotov to prevent the destruction of records that he argues could curb research into the history of Soviet political repression.

Fedotov promised to “always defend keeping archive materials that contain highly important historical information” as a way to “counter the falsification of history.”

“But when there’s no document, you can make up anything you want,” he warned.