Legal provisions for disclosure and challenge of arbitrator are very crucial to restore the confidence of the parties in the arbitral process when it is upset by complaints of lack of independence or impartiality of arbitrators. However, detailed and binding rules on the challenge and disqualification of arbitrators are not forthcoming. Against this backdrop, the revised Indian Model Bilateral Investment Treaty (BIT) of 2015, as a first-of-its-kind, has taken the initiative of including a detailed framework in the form of treaty rules to address the disclosure requirements and the grounds and procedure for challenge of arbitrators. In this connection, the article attempts to determine how the disclosure and arbitrator challenge mechanisms are structured across the leading international (investment) instruments and later use this as a benchmark to evaluate the disclosure obligations of arbitrators and their challenge under the Indian Model BIT.