2. . Water related services revenue The Auditor-General identified the following: a) An amount of R231 791 894 relating to "return to sender" invoices was excluded from water related services revenue. b) The South African Statement of Generally Accepted Accounting Practice (GAAP) and the International Accounting Standards (IAS) 18 require that revenue should be recorded when it is probable that economic benefit will flow to the entity. c) There was an inadequate system of control to assess the probability of recording these amounts as revenue which is reliable for audit purposes. d) Audit evidence to support the completeness of water related services revenue of R1 643 715 as disclosed in the statement of comprehensive income could not be obtained sufficiently.