The Serious Fraud Office is proposing to get rid of six roles as part of wider public service cost-cutting measures.
It is consulting with staff on a proposal to disestablish 12 roles - five of which are vacant - and create six new roles, as part of what it called an "organisational efficiency and effectiveness review".
The organisation employed 73 staff, and that number had been stable for the last few years, Public Service Commission data showed.
"As a small organisation, the SFO has always run a lean and efficient operation with most staff on the front line of our efforts to tackle fraud and corruption," a spokesperson for the office said.
"However, the SFO needs to adapt to the fiscal environment and ensure resources are efficiently allocated."
The Public Service Association said the strategy and prevention, forensic services and legal teams were affected, but the Serious Fraud Office could not confirm that.
But it said no front-line jobs would go.
The government was forcing the SFO to cut jobs which undermined its ability to fight white collar crime, which impacted thousands of New Zealanders every year, the PSA's national secretary Duane Leo said.
"Fraud is rising fast, yet the government promised to be 'tough on crime' so this just doesn't add up - fraud will only keep hurting more New Zealanders," he said.
"The office told the minister it was already 'lean and efficient' so how can it properly do its important work in the face of these cuts?"
So far, RNZ has tallied a net loss of more than 6500 roles in the public service.
The public sector workforce has grown by 15 percent in the past five years, and the National Party campaigned on slashing "back-office expenditure".
Prime Minister Christopher Luxon said savings across the public sector were being reinvested in front-line services and tax reductions.