asked Her Majesty's Government:
Whether they will keep central records of persons detained under the immigration laws in the belief that they were foreign nationals liable to deportation, and who were subsequently found to be either (a) British, or (b) otherwise exempt from deportation. [HL928]
Detention reviews of those detained under immigration laws with a view to deportation are carried out on a case-by-case basis according to the specific individual circumstances of the detainee to ensure that detention is lawful and meets our current criteria on detention. Reviews are carried out on a monthly basis to ensure that the individual continues to meet the requirements for detention. Collating this information on a central basis in order to record details of those who were initially determined to be liable for deportation but then found not to be would require a significant use of resources at disproportionate cost.