Auditor-General Kevin Brady has found Christchurch City Council's decision-making process in buying five central city properties from a local developer last year was sound.
The decision to buy the properties, at a cost of $17 million, was made in July last year.
The five sites are owned by developer Dave Henderson.
After widespread criticism and several informal complaints, Mr Brady's office decided to investigate.
Mr Brady found that the council's decision-making process complied with the Local Government Act 2002.
He says the merits of the decision to buy the sites were a matter for the council's elected members.