An investigation has opened into allegations Ministry of Justice (MoJ) staff illegally accessed computer files related to the Nottingham attacks.
Students Barnaby Webber and Grace O'Malley Kumar were fatally stabbed by Valdo Calocane in the city in June 2023 along with school caretaker Ian Coates.
Calocane, who had been diagnosed with paranoid schizophrenia, received a hospital order in January after admitting manslaughter on the grounds of diminished responsibility.
Now the South East Regional Organised Crime Unit is examining whether case files were accessed illegally by government employees.