17. The methodology adopted by the Inquiry is set out in Annex 1. Core participant status was granted under Rule 5 of the Inquiry Rules 2006 to 16 core participants, including eight victims.

18. The seven topics considered in this investigation were derived from the scope of the investigation set by the Inquiry,^[1] and the Terms of Reference for the Inquiry set by the Home Secretary.^[2]

19. In addition to two preliminary hearings, public hearings were held over 14 days in March 2019.

20. At the public hearings, we heard an account from one victim, Robert Montagu, about his experiences as a child who had been sexually abused. Evidence was also provided by institutional witnesses about a wide range of factual matters. These witnesses included retired and serving police officers, civil servants, politicians and journalists.

21. Various institutions also supplied corporate statements and documents, including the Metropolitan Police Service, the IOPC, the Crown Prosecution Service, various government departments, the Security Service, the Secret Intelligence Service, Government Communications Headquarters (GCHQ), and all the Westminster political parties. Finally, the Inquiry reviewed a large amount of witness and documentary evidence, which was disclosed to core participants where relevant and which has been published on the website if it was referred to during the public hearings or in this report.