Three staff of the now-defunct Canterbury Earthquake Recovery Authority (CERA) are being investigated over claims they used their position for personal financial advantage, the minister responsible says.
The Minister in charge of Christchurch's rebuild, Gerry Brownlee said the allegations were damaging for New Zealand's reputation.
Three staff members from the dismantled authority have been accused of trying to arrange property deals through their own company for a finders fee.
"It is undeniable that there was a company formed for a purpose by three people who were employed by CERA so that alone is enough to investigate the activity, because that activity would be unacceptable," Mr Brownlee said.
"But I want to make really clear that we are not leaving any stone unturned because these are the sort of allegations that are reputationally damaging for the whole of New Zealand."
Investigations by the Prime Minister's Department and the State Services Commission were under way, Mr Brownlee said.
He said the allegations were deeply disappointing.
Labour's Canterbury spokesperson Megan Woods said Mr Brownlee, who oversaw the authority, should have known what was happening under his nose with senior staff in the organisation.
Ms Woods said there needed to be a full and thorough investigation into the allegations and, if appropriate, someone held to account.