The second investigation led to another three workers being sacked but no evidence of a widespread "systemic problem".
"None of these staff gained financially and their actions were not illegal," Winz deputy chief executive Debbie Power wrote.
"However, they were in breach of the zero-tolerance policy and for that reason they lost their jobs."
One of the fired workers emailed their partner, who does not work for the ministry, to say someone they knew had applied for a benefit.
The second emailed an associate, who works in another government department, about a client.
The third sacked staff member accessed and processed records of people they knew.
None financially benefited.
Six other staff received code-of-conduct warnings after the review, as there was evidence of inappropriate access to client files which were described as "lapses of judgment".
CRACKING DOWN
November 2011: Seven Work and Income staff sacked from Manukau Office.
December 2011: National review ordered and 100 staff randomly audited.
July 2012: Three more staff sacked. Six others receive code-of-conduct warnings.
