Senior staff at the Christchurch City Council have been shown to have manipulated or removed information that they feared would look bad for the council.
An investigation by the chief ombudsman has revealed behaviour that he describes as "deeply concerning".
Judge Peter Boshier's report particularly takes aim at former chief executive, Karleen Edwards, who left the job this year, for failing to deal with the problem.
The new chief executive Dawn Baxendale says she accepts the reports findings and is committed to implementing the ombudsman's 39-step improvement plan.
Judge Boshier is in our Wellington studio.