There is no difference in how privilege operates in civil or criminal proceedings, although there are nuances relating to who determines whether a document is privileged when privilege is claimed.

In civil proceedings, it is generally the case that the courts are the ultimate arbiter over whether a document is privileged when a party has refused production of a document by asserting privilege.

In criminal proceedings, however, there is recent dicta by the Singapore High Court that where documents have been lawfully seized by the police and a claim of privilege is asserted over the seized documents, the Attorney-General's Chambers rather than the court should conduct an initial review of seized materials for legal professional privilege. The Attorney-General's Chambers should conduct this initial review if the lawyer and/or their clients' claim to legal professional privilege was not accepted by the Attorney-General's Chambers at face value, or if there was a reasonable basis to think that legally privileged material would be encountered in a review of seized material, even if there was no specific claim of legal privilege. The High Court further observed that the review should be conducted by a team of Attorney-General's Chambers officers who are not, and will not be, involved in the underlying investigation. Once the Attorney-General's Chambers has conducted its initial review of any claims of privilege, this will ensure that only narrowly defined disputes as to privilege are brought to court for the court's determination.

In the same High Court decision, the court observed that the Evidence Act and the Criminal Procedure Code did not contain provisions prohibiting the seizure and review of legally privileged material, in contrast to the UK's position, where the police are prohibited by law from seizing material which they reasonably suspect to be legally privileged.

It is presently unclear whether there are any differences in how legal professional privilege operates in regulatory situations. The Evidence Act is silent on this issue.

The issue of whether notes of interviews with employees and other documents produced during investigations are covered by privilege remains unclear in Singapore. However, the Singapore Court of Appeal has endorsed an Australian decision recognizing that certain communications from third parties were protected by legal advice privilege, depending on the function of the third party rather than the nature of the relationship between the third party and the party that engaged it.

However, it should be noted that the Singapore courts have not conclusively decided on this issue. The contrary English position, where the English courts have suggested that an employee is only considered the "client" for the purposes of legal advice privilege where they can be considered the "directing mind and will of the corporation", may still prove to be persuasive.