Arbitrators’ Independence and Impartiality – Non-Disclosure, Bias, Hostile Conduct? Can the Award Be Annulled?

An arbitrator’s bias that casts doubt on its impartiality “in the mind of the parties” must be proven by hard evidence.

In its decision of 3 October 2023, the Paris Court of appeal rejected the Republic of Cameroon’s application for annulment of the final award of 22 September 2021 made in favour of Garoubé.

The Republic of Cameroon argued that the chairman of the arbitral tribunal was pro-investor biased for two reasons: the chairman did not properly satisfy his disclosure obligation and conducted the proceedings in an “hostile” manner vis à vis the Republic of Cameroon.

The decision of the Paris Court of Appeal dealt with the two branches of the arbitrator’s independence and impartiality; first the duty to disclose all situations that “in the eyes of the parties” may cast doubt on the arbitrator’s independence and impartiality and, second, the obligation to conduct the proceedings with impartiality. The alleged hostility of the chairman towards a party shows a bias which demonstrates an absence of impartiality.

The Court rejected the application, considering first that the claim for lack of disclosure was inadmissible because it must first be raised before the arbitral tribunal, which was not the case, and second that the alleged hostile conduct of the chairman was not substantiated.

It follows that the notion of circumstances that “in the eyes of the parties” or “in the mind of the parties” cast doubts on the impartiality or independence of an arbitrator, is not a mere question of perception by a party and must be supported by hard evidence to convince the Court.

My detailed analysis of this case was published online on 26 October 2026 on Lexis®PSL and is available here (subscription required)