The Public Service Association (PSA) wants the Government to apologise to two senior diplomats, wrongly accused of a leak at the Ministry of Foreign Affairs and Trade.
It comes after a damning report by the ombudsman on an investigation led by Paula Rebstock which targeted Derek Leask and Nigel Fyfe, despite evidence the leak came from the State Services Commission (SSC).
The ombudsman found Mr Leask and Mr Fyfe were innocent victims of a witch-hunt to discover who leaked material from the Ministry of Foreign Affairs and Trade.
PSA national secretary Glenn Barclay says those responsible need to say sorry.
"This is a long list of problems, so we think that he definitely needs an apology and we agree with the ombudsman on that."
Mr Barclay hopes the Government and SSC will learn from their failings.
Former diplomat Michelle Wanwimolruk says Mr Leask should be compensated, after shouldering "great personal and financial costs" over the last four years because of the SSC's actions.
She says New Zealanders should question why this serious abuse of power occurred.
"I recall there was an atmosphere of anxiety. Many of my colleagues called Paula Rebstock's inquiry a witch-hunt. It seemed like the SSC were unfairly looking for and punishing people in order to set an example," she said in a statement.
"We should all be concerned about our democratic conventions. Civil servants are meant to provide free and frank advice. When Government officials are singled out, unfairly accused and publicly shamed -- all of New Zealand should be concerned."