Doctrine of bias in Singapore law

Bias is one of the grounds of judicial review in Singapore administrative law which a person can rely upon to challenge the judgment of a court or tribunal, or a public authority's action or decision. There are three forms of bias, namely, actual, imputed and apparent bias.

If actual bias on the part of an adjudicator can be proved, the High Court can quash the decision. Cases of actual bias are rare due to the difficulty of proving the existence of a prejudiced judicial mindset. Imputed bias arises when a decision-maker has a pecuniary (monetary) or proprietary (property related) interest in the decision he or she is charged to adjudicate. The courts have also extended the category of imputed bias to situations where adjudicators have personal, non-pecuniary interests in decisions. The existence of a situation leading to an imputation of bias warrants the decision-maker being automatically disqualified.

Even if actual or imputed bias cannot be proved, an appearance of bias is sufficient for a judgment or decision to be set aside. The legal test for establishing apparent bias in Singapore has been the subject of some controversy. In the cases of Jeyaretnam Joshua Benjamin v. Lee Kuan Yew (1992) and Tang Liang Hong v. Lee Kuan Yew (1997), the Court of Appeal stated that the test should be "reasonable suspicion", that is, the court should ask itself whether "a reasonable and fair-minded person sitting in court and knowing all the relevant facts [would] have a reasonable suspicion that a fair trial for the applicant was not possible". However, after a number of cases which established that a "real likelihood" test should be applied in the UK, the High Court in Tang Kin Hwa v. Traditional Chinese Medicine Practitioners Board (2005) expressed the obiter view that there was in fact no material difference between the two tests. In Re Shankar Alan s/o Anant Kulkarni (2006), a different High Court judge disagreed with this view, holding that the reasonable suspicion test is less stringent as it requires a lower standard of proof than satisfaction on a balance of probabilities. He expressed preference for the reasonable suspicion test over the real likelihood test. As of January 2013, the Court of Appeal had not yet ruled on the matter.