The cost of detention.

Immigration detention is one of the most significant administrative deprivations of liberty Hong Kong undertakes. The facilities exist, the budgets are approved through Legislative Council processes, and operating cost data is periodically published in Finance Committee responses and the annual estimates. A valuable body of public information exists — including the substantial research published by Professor Surabhi Chopra, whose work on Hong Kong's immigration detention regime has mapped much of the public record and is preserved as an open data repository at immigrationdetentionhk.net. Our clinic's work builds on that existing record rather than starting from scratch.

The question we are interested in is the cost of detaining asylum seekers. Within that, we examine when it is reasonable and fair to detain and when it is not, what alternatives to detention exist, and whether detention is a useful deterrent to abuse of the USM system.

This page sets out what the public record currently shows on the fiscal dimensions of that question — the cost per detainee, the facility-level operating costs, the expansion of the detention estate, and the scale of associated litigation. It is one of several ongoing projects in the clinic's USM & refugee rights practice area, and the analysis will be updated as further data becomes available.

From 2016–17 to 2019–20, the daily cost per detainee at CIC grew steadily but moderately — roughly 5% a year. Between 2019–20 and 2020–21, the figure rose by 49% in a single financial year. The Immigration Department's own note on the data attributes this partly to reduced detainee numbers during Covid-19 (the denominator fell, because the facility operated at approximately half its 500-person capacity), and partly to increased manpower and replacement works undertaken at the facility during the same period.

What is notable is that the cost continued to rise after the pandemic — to HK$1,450 per detainee per day in 2021–22, and HK$1,672 in 2022–23. The public record does not yet contain a comparable breakdown for 2023–24 or 2024–25. Understanding what drove the post-pandemic continuation of the upward trajectory would be valuable, and we will update this analysis as further data is released.

Immigration detention in Hong Kong operates across two distinct administrative structures. Two facilities are managed directly by the Immigration Department, and two are managed by the Correctional Services Department (CSD) but used to detain persons under the Immigration Ordinance. The distinction matters: each operator publishes statistics differently, applies different operational rules, and is subject to different oversight regimes.

The Immigration Department publishes detention statistics for its two managed facilities at www.immd.gov.hk/eng/facts/cic.html and www.immd.gov.hk/eng/facts/tkoidc.html. The 2025 figures published by the department are reproduced below.

The Immigration Department also publishes admission figures by country or region for both managed facilities. The clinic has compiled this data — building on earlier work by Professor Surabhi Chopra's research project at CUHK — and reproduces the 2025 breakdown below. Across both facilities, admissions are concentrated in a relatively small number of nationalities, with Chinese Mainland and Indonesian nationals together accounting for more than half of all admissions in 2025.

The pattern of admissions across the two Immigration Department-managed facilities is broadly similar. The largest groups in both facilities are Chinese Mainland nationals and Indonesian nationals, followed by South and Southeast Asian nationalities. We report the two facility-level totals separately — CIC at 6,572 and TKOIDC at 4,664 in 2025 — and do not combine them, because the published statistic is an admissions count rather than a headcount, and individuals transferred between the two facilities would be counted in each. Equivalent nationality data is not published for the CSD-managed facilities; for those, the clinic obtained a separate headcount series through its own Access to Information request, set out below.

The Immigration Department publishes statistics for the facilities it manages directly. The two CSD-managed institutions — Tai Tam Gap and Nei Kwu — publish no equivalent series. To close that gap, the clinic's students submitted an Access to Information request to the Correctional Services Department for two things: the annual expenditure on persons detained under the Immigration Ordinance in CSD-managed facilities, and the number of persons so detained, from April 2021 to the present.

The Department's response, received in 2026, is itself a finding. The request for expenditure data was refused: the CSD stated that it does not maintain spending broken down by type of person in custody, and that it was therefore "not practicable to accurately calculate the expenditure spent on any particular type" of person in custody. The request for detainee numbers was met. Those figures are reproduced below.

Two things stand out. First, the population held under immigration powers in CSD facilities has grown almost fourfold in four years — from 98 at the end of 2021 to 376 by February 2026 — with the steepest jump between 2022 and 2023, coinciding with Nei Kwu's incorporation into the detention estate. Unlike the Immigration Department's admissions figures, these are snapshot headcounts on a given date, so they describe the standing population rather than the annual flow through the facilities.

Second, the refusal of the cost request leaves a deliberate gap in the public record. The clinic's research can establish how many people are held under immigration powers in CSD facilities, but not what their detention costs the public — because the operator that holds the spending data does not disaggregate it. The contrast with the Immigration Department's published per-detainee cost figures for CIC is itself part of the picture: the same question, asked of two operators of the same detention estate, produces a published answer from one and a refusal from the other.

These figures show claims lodged, not claims succeeding. The Court of Final Appeal's decision in Ghulam Rbani v Secretary for Justice for and on behalf of the Director of Immigration (2014) 17 HKCFAR 138 — adopting the Hardial Singh principles in the context of administrative detention under section 32(2A)(a) of the Immigration Ordinance — established the framework within which a significant portion of these claims are resolved, and the government has indicated in subsequent litigation that the majority of claims arising under that line of authority have been disposed of by sanctioned offers, settlements, or without-prejudice negotiations rather than final adjudication.

The series spans nineteen financial years and shows three broad phases. From 2006–07 to 2008–09, only single-figure or zero claims were recorded in any year. From 2009–10 onwards, claim volumes rose sharply and then settled into a sustained but volatile pattern, peaking at 614 in 2015–16 before fluctuating between roughly 67 and 289 across the following five years. The most recent two financial years on record show a renewed sharp rise: 473 claims in 2023–24, and 992 in 2024–25 — the highest annual total in the dataset.

What the chart shows is therefore a volume signal rather than a direct measure of unlawfulness. It nonetheless tracks the ongoing administration of a substantial litigation caseload, and the rise across the most recent years sits in the public record without further explanation. Understanding the breakdown of outcomes — settled, succeeded, failed — and the amounts involved would help policymakers and researchers situate these figures within the wider fiscal and administrative picture of detention.