The Singapore High Court recently confirmed in Mah Kiat Seng v Attorney-General  SGHC 202 (Mah Kiat Seng) that the common law doctrine of public interest immunity remains part of Singapore law and was not superseded by the enactment of the Evidence Act (Cap. 97) (EA) in 1893. The Court also clarified how the common law doctrine of public interest immunity interacts with the statutory framework of the EA – in particular, sections 125 – 127 of the EA.
The Mah Kiat Seng decision also has wider implications beyond its factual context and is a welcome clarification for corporates providing confidential material to government authorities and agencies in Singapore, including in the context of a regulatory investigation. The judgment sets out the boundaries of when a public authority is entitled to invoke public interest immunity to withhold the disclosure of evidence, which may otherwise have to be disclosed under the rules of civil or criminal procedure. Such clarity will likely help corporates assess the risk of potential disclosure (in subsequent civil or criminal proceedings) of confidential material provided to government authorities and agencies in Singapore.
That said, Mah Kiat Seng may not be the last word on the status of public interest immunity in Singapore law, given the previous conflicting decision in BSD v Attorney-General  SGHC 118. The position would benefit from a definitive Court of Appeal ruling on the issue, or a move by Parliament to codify the doctrine of public interest immunity under the EA.
In Mah Kiat Seng, the Plaintiff was apprehended and taken into custody by the Singapore Police Force (SPF) under section 7 of the Mental Health (Care and Treatment) Act. The Plaintiff later sued the SPF and two of its officers on various grounds, including wrongful arrest and false imprisonment, and sought discovery of closed-circuit television camera (CCTV) and body-worn camera (BWC) recordings of his apprehension and detention.
At first instance, the Assistant Registrar agreed with the Attorney-General that, as a compromise, the CCTV footage may be inspected at the Police Cantonment Complex but copies cannot be taken, whereas copies of the BWC recordings can be provided but with pixelation prior to inspection so as to protect the complainant’s identity. The Plaintiff appealed to the High Court.
The legal issues before the Court on common law public interest immunity
The Attorney-General’s initial argument on appeal was that the CCTV and BWC recordings were absolutely protected from disclosure pursuant to section 126 of the EA, which provides “[n]o public officer shall be compelled to disclose communications made to him in official confidence when he considers that the public interest would suffer by the disclosure”. However, the High Court expressed doubt as to whether camera footage and recordings fell within the meaning of “communications”. Upon further submissions on the scope of section 126 of the EA, the Attorney-General accepted that the CCTV and BWC footage was not, in and of itself, “communications” within section 126 of the EA and instead submitted:
- that section 126 of the EA still applied to such footage which recorded a communication, as was the case with some of the BWC footage; and
- as a fall-back argument, that where section 126 of the EA did not apply, the government was entitled to invoke public interest immunity against disclosure of the CCTV and BWC recordings under the common law.
In relation to the latter argument, the Court directed further submissions from parties and appointed an amicus curiae to deal with two broad issues of law:
- Whether common law public interest immunity is part of Singapore law – and, in particular, whether its applicability was affected by the enactment of the EA;
- If common law public interest immunity is part of Singapore law, how the doctrine is to be invoked and what the appropriate test is.
Common law public interest immunity survived the enactment of the Evidence Act and remains part of Singapore law
For background, the existence of the common law doctrine of public interest immunity under Singapore law is complicated by the fact that Singapore’s rules of evidence are codified by the enactment of the EA in 1893; section 2(2) of the EA provides that “[a]ll rules of evidence not contained in any written law, so far as such rules are inconsistent with any of the provisions of this Act, are repealed.”
In Mah Kiat Seng, Philip Jeyaretnam JC confirmed that the common law public interest immunity remains part of Singapore law.
- Common law public interest immunity has its roots in “Crown privilege” under English law, which then evolved into “public interest immunity”, a duty exercised in the public interest to refuse disclosure of the information (Rogers v Home Secretary  1 AC 388).
- While section 2(2) of the EA operated to repeal certain common law rules of evidence, Jeyaretnam JC held that common law public interest immunity is not “inconsistent with any provisions of the [EA]” and therefore was not repealed by operation of section 2(2) of the EA.
- Further, sections 125, 126 and 127 of the EA may be viewed as “instantiating” that common law doctrine in the statutory framework of the EA. Jeyaretnam JC noted that this view is supported by ARW v Comptroller of Income Tax  1 SLR 499 (ARW), where the Court of Appeal accepted that the AG retained a right to object to disclosure of information by public officers on the ground of “public interest privilege”, even though such a right was not expressed in the EA.
In this regard, while Mah Kiat Seng departs from contrary dictum in another decision of the High Court in BSD v Attorney-General  SGHC 118 (BSD), Jeyaretnam JC justified his disagreement on two grounds. First, the Court of Appeal’s decision in ARW does not appear to have been cited to the Court in BSD. Second, the arguments tentatively accepted by the Court in BSD were unduly narrow in its focus on the technical differences between the operation of common public interest immunity and section 125 of the EA, whereas a conceptual and purposive view of section 125 of the EA should have been taken.
The applicable test for common law public interest immunity
Having held that common law public interest immunity remains part of Singapore law, Jeyaretnam JC went on to consider the applicable test for common law public interest immunity and the requirements for invoking common law public interest immunity, holding that:
- whether public interest immunity can be invoked involves a balancing exercise as to whether the public interest against disclosure is outweighed by the public interest in the administration of justice;
- such a test is to be determined on a case-by-case basis upon consideration of all relevant factors, including (a) the degree of relevance of the information, (b) the specific risks arising from disclosure, and (c) the harm to the public interest should such risks eventuate – the Court is also entitled to consider whether the risks weighing against disclosure may be mitigated by appropriate safeguards;
- where the disclosure of footage may disclose the identity of informants, section 127 of the EA may operate – otherwise, the Court must decide whether common law public interest immunity applied in light of the strong public interest in withholding the identity of identity of informants, as against countervailing interests such as whether there is significant information in the footage that may bear on the accused’s innocence;
- procedurally, if a Court is asked to determine whether public interest immunity is available on a particular set of facts, the Court has the power to view the document or information in question, save for documents which refer to “affairs of State”, pursuant to section 164 of the EA; and
- as to standing to claim common law public interest immunity, Jeyaretnam JC held that a Court may either act on its own initiative if it perceives possible serious injury to the national interest from disclosure, or to act on the request of any person or office-holder of “sufficient senior[ity] and [who is] adequately separated from and independent of any alleged misconduct” – this may include the relevant Minister, head of department or chief executive of a statutory board, as well as the Attorney-General, as custodian of the public interest.
 For convenience, these provisions read as follows:
Evidence as to affairs of State
- No one shall be permitted to produce any unpublished official records relating to affairs of State, or to give any evidence derived therefrom, except with the permission of the officer at the head of the Department concerned, who shall give or withhold such permission as he thinks fit, subject, however, to the control of the Minister.
126.—(1) No public officer shall be compelled to disclose communications made to him in official confidence when he considers that the public interest would suffer by the disclosure.
(2) No person who is a member, an officer or an employee of, or who is seconded to, any organisation specified in the Schedule to the Official Secrets Act (Cap. 213) shall be compelled to disclose communications made to him in official confidence when he considers that the public interest would suffer by the disclosure.
Information as to commission of offences
127.—(1) No Magistrate or police officer shall be compelled to say whence he got any information as to the commission of any offence.
(2) No revenue officer shall be compelled to say whence he got any information as to the commission of any offence against the public revenue or the excise laws.
 Mah Kiat Seng, paras. 54-56
 Mah Kiat Seng, paras. 57-60
 Chua Lee Ming J in tentatively accepted a submission that this meant common law public interest immunity no longer formed part of Singapore law, as it was not contained in any written statute and was inconsistent with s 125 of the EA.
 Mah Kiat Seng, para. 80
 Mah Kiat Seng, paras. 81-82
 Mah Kiat Seng, para. 86
 Mah Kiat Seng, para. 82
 Mah Kiat Seng, paras. 83-85
 Mah Kiat Seng, para. 89