ACO18 v Minister for Immigration, Citizenship and Multicultural Affairs

The case of ACO18 v Minister for Immigration, Citizenship and Multicultural Affairs involved the applicant, ACO18, challenging a decision made by the Immigration Assessment Authority (IAA) under the Migration Act 1958 (Cth). The applicant sought a protection visa and submitted new information during the review process. The primary issue before the court was whether the IAA erred in its assessment of the credibility of the new information provided by the applicant, specifically whether the IAA misconstrued section 473DD(b)(ii) of the Act by evaluating the truth of the new information instead of its capacity to be believed. The applicant argued that this error was material and could have led to a different outcome regarding his claims.

The court examined the IAA's reasoning and found that the Authority had indeed misconstrued the statutory requirement by imposing a higher standard of satisfaction than required by the Act. The IAA assessed the new information based on its truth rather than its credibility, which is the appropriate standard under section 473DD(b)(ii). The court held that the IAA's error was material because there was a realistic possibility that had the IAA not erred, it might have reached a different conclusion about the applicant’s claims. This conclusion was based on the standard of "reasonable conjecture," as outlined in Nathanson v Minister for Home Affairs.

As a result of the court's findings, the IAA's decision was quashed, and a writ of mandamus was issued to require the IAA to reconduct the review of the delegate’s decision according to law. The court also ordered that the Minister pay the applicant's costs, to be agreed upon or, in the absence of agreement, according to the scale set out in the Federal Circuit and Family Court of Australia (Division 2) (General Federal Law) Rules 2021 (Cth).