Data Vault: 64 Million Hidden Files Discovered at Belastingdienst

Executive Summary

The Belastingdienst discovered a digital “data vault” (datakluis) containing at least 64 million files that were never examined during the parliamentary investigations into the toeslagenaffaire. The vault was created in 2019 as a privacy-compliant measure, then vanished from institutional oversight until July 2025. State Secretaries Eerenberg and Palmen informed parliament on April 15, 2026 — nine months after the discovery — triggering outrage across the political spectrum.

What Happened

In 2019, the Belastingdienst created an isolated digital storage environment to segregate files that staff should no longer access while preventing premature destruction of files that required permanent retention. This was an AVG-related measure. After creation, the data vault “somehow disappeared from sight.” It was rediscovered at the Ministry in July 2025, but was initially unsearchable — “a key had to be found first” to access it.

When samples were finally examined, documents emerged that should have been provided to the parliamentary inquiry committees. State Secretaries Eerenberg (Finance) and Palmen (Recovery Toeslagen) sent a letter to the Tweede Kamer on April 15, 2026. Palmen assured parliament that the data vault would have no consequences for affected parents — their own stories remain the starting point, and compensation does not need to be repaid even if contradictory information emerges.

Evidence

(1) The vault contains 64 million unsorted files; (2) Created in 2019 as an AVG mitigation measure; (3) Rediscovered July 2025 at the Ministry; (4) Files were unsearchable upon discovery; (5) Sample checks confirmed documents relevant to the parliamentary inquiry were present; (6) Nine-month delay between discovery and parliamentary notification; (7) Independent investigation has been commissioned; (8) Palmen pledged clarity “before summer 2026.”

Analysis

This discovery raises fundamental questions about the completeness of all prior investigations. The PEFD (Parlementaire Enquête Fraude en Dienstverlening) was formally concluded, but these 64 million files were never examined. The nine-month delay in notifying parliament directly impacts trust between cabinet and legislature — trust that was already described as “fragile” in this dossier. CDA MP Inge van Dijk asked: “Was that a conscious choice or is this a failure?” VVD coalition partner Van Eijk called it “very serious.” DENK and SP raised suspicions of a cover-up. The technical explanation that a “key” was needed to access the vault raises further questions about why 9 months were required.

Sources

• NOS, 15 april 2026: Belastingdienst vindt datakluis met mogelijk relevante bestanden toeslagenschandaal
• NOS, 16 april 2026: Kamer boos over opduiken datakluis toeslagenschandaal
• Kamerbrief Eerenberg/Palmen, 15 april 2026
• Rapport 16 — Datakluis AVG Maatregelen Toeslagen (blg-1197678)