Recently, the Singapore Court of Appeal in CBS v CBP  SGCA 4 held that an arbitrator's denial of witness evidence at a hearing constituted to a breach of natural justice.
The case stemmed from an arbitration under the Rules of the Singapore Chamber of Maritime Arbitration (“SCMA Rules”). Despite not filing any witness statements, the respondent requested a hearing to present its oral witness evidence. However, the arbitrator would determine if such hearing was necessary only after the respondent had submitted its witness statements. This is so to allow the arbitrator to evaluate if there was “substantive value” in holding a hearing with witnesses. When the respondent refused to submit the witness statements, the arbitrator convened a hearing for a hearing without any witnesses purportedly under Rule 28.1 of the SCMA Rules and subsequently issued an award in favour of the claimant.
The respondent then applied to set aside the arbtral award in the High Court. The High Court evinced that there had been a breach of natural justice, and held that the respondent was prejudiced by the breach, as such the final award was set aside. This decision was appealed to the Court of Appeal.
The Court of Appeal reaffirmed that "the parties' right to be heard in legal proceedings is a fundamental rule of natural justice", citing Article 18 of the UNCITRAL Model Law, which requires each party to have a "full opportunity" to present its case. The Court recognized that tribunals generally have broad case management powers. However, excluding the entirety of a party's witness evidence, in cases where the applicable rules do not give the arbitrator such express authority, constitutes a serious breach of natural justice. In other words, tribunals must provide the parties an opportunity to present witness evidence at a hearing if they wish to do so, or risk having the arbitral award set aside.