An administrative authority must comply with section 3 of the Administrative Justice Act by acting lawfully, reasonably, and fairly, which includes providing adequate notice of proposed action, giving affected persons a reasonable opportunity to make representations, and supplying written reasons for decisions. A creature of statute can only validly do what the enabling statutory framework gives it capacity to do and cannot usurp functions vested in other statutory bodies. Under the Money Laundering and Proceeds of Crime Act, powers to investigate suspicious transactions and seize funds are vested in the Financial Intelligence Unit and ZimRA, not the Reserve Bank's internal divisions. For an affidavit to be valid, the deponent must take the oath in the presence of the commissioner of oaths, and both must append their signatures contemporaneously at the stated location, as required by the Justices of the Peace and Commissioners of Oaths Act. Locus standi requires a direct and substantial legal interest that is actual, current, and not too remote - a party whose funds are frozen and whose business operations are crippled has standing to challenge the decision.