A privacy expert warns there are several legal traps government agencies could fall into using fake social media profiles to gather intelligence.
The Ministry of Business, Innovation and Employment (MBIE) is defending itself after revelations it's spending more than $100,000 teaching staff to sleuth online.
ZX Security Limited is teaching staff how to take material from online platforms like Facebook and LinkedIn, maintain multiple online personas and extract GPS coordinates from photos.
Gehan Gunasekara from the Privacy Foundation says it's a grey area.
"It's a question of the specific context, how serious was the illegal behaviour targeted, and was it proportionate?"
MBIE says it is to protect staff carrying out the investigations.
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- The question of social media and privacy
Mr Gunasekara says agencies can't have free rein.
"We need to think about the guidelines, we need to have safeguards and we need to have ongoing vetting and auditing of these practises."
The Government says it's questioning MBIE officials over the training programme.
Mr Gunasekara says there needs to be a hard line on intelligence tactics.
"I think it's better to have a systemic approach to privacy, rather than waiting for the person to fall off the cliff."
So far 70 staff have been through the course, which is set to continue through to 2021.