Documents show an employee of HMCTS was so concerned, they raised a formal whistleblower complaint, which prompted a further internal investigation.

This was led by a senior IT professional from the Prison Service and resulted in a detailed report, distributed internally in November 2024.

This is the report that has been leaked to the BBC.

It was set up to “establish the facts” on data loss and data corruption issues affecting the Social Security and Child Support Tribunal.

Investigators interviewed 15 witnesses, including software engineers and developers, and reviewed internal documents, such as incident logs and diary entries.

It found “large scale” data breaches that should have been addressed “as soon as they were known”. However, the report said that HMCTS had taken several years to react despite multiple warnings from senior technical staff, from 2019 onwards.

Investigators concluded that because HMCTS had not undertaken a comprehensive investigation, the full extent of data corruption was still unknown, including if case outcomes had been affected.

The report added that data loss incidents continue to be raised against the IT system used by the civil, family and tribunal courts.

The concerns raised in the leaked report echo those raised by those speaking to the BBC.

Sources inside HMCTS express concerns that missing evidence may have gone undetected.

“This is quite a frightening possibility,” one told the BBC, “That information gets lost, no-one notices, and there is a miscarriage of justice. I think that has to be the biggest worry.”