Disappearance of sensitive files of top law enforcement officials has sparked a crisis at Europol.

They were supposed to be under lock and key, in a secure storage room deep inside Europol’s headquarters in The Hague.

But a clutch of highly sensitive files containing the personal information of top law enforcement executives went missing last summer.

Europe’s law enforcement agency has been mired in a whodunit ever since.

According to an internal agency note seen by POLITICO, and conversations with current and former staff, the hardcopy personnel files of Europol Executive Director Catherine De Bolle and other senior officials leaked sometime before September.