A spreadsheet containing details of 25,000 Afghan asylum applicants, MPs, and senior military officers was mistakenly sent out in February 2022.
The incident put hundreds of thousands of Afghans at risk and was a “clear breach of strict data protocols”, Mr Healey said.
Following the breach, a relocation scheme for over 16,000 Afghans was implemented at a cost of £6 billion, with details released only after a superinjunction was lifted.