Thames Valley Police acknowledged Tuesday that a decade-long internal guidance document incorrectly advised officers that investigations involving former members of the Royal Family carried inherent property access privileges under common law.

The force released a 2014 operational memo stating that individuals retaining courtesy titles after removal from senior royal duties occupied "a transitional constitutional category" permitting search procedures "consistent with Crown premises protocols." The document advised that former princes and princesses should be approached with "flexible evidential thresholds" due to their "proximity to sovereign immunity."

Detective Chief Superintendent Malcolm Hendricks told reporters the guidance emerged from a workshop on handling cases involving titled individuals. Three separate units had independently developed the assumption that royal styling conveyed special procedural status, leading to its codification in training materials. When Thames Valley officers obtained warrants to search Andrew Mountbatten-Windsor's properties in February, supervisors believed they were following established protocol for subjects whose status fell "between fully royal and conventionally civilian." The High Court ruled Monday that the warrants were obtained under incorrect legislation.

Force spokesman DCI Patrick Woolridge said investigators now understand that former senior royals retain "essentially the same Fourth Amendment protections as sitting Barons or above," though he acknowledged uncertainty about whether that comparison applied to life peers versus hereditary titles. The force has commissioned external review of its procedures for handling approximately forty categories of titled individuals, from Knights Bachelor through to Dukes, after discovering that different units applied different standards based on whether subjects held their positions through royal appointment or parliamentary creation.

Chief Constable Rebecca Thornhill announced a comprehensive audit of previous searches involving anyone listed in Debrett's Peerage. She confirmed the force is examining whether similar confusion affected cases involving High Sheriffs, Lord-Lieutenants and individuals with papal honors. The review will determine whether officers require remedial training on the 1998 Human Rights Act, which Thornhill noted "does not contain the aristocratic exceptions we believed were implied in Section 8."