An imprisoned gang member organised a bar tab for Corrections guards drinking at a pub after hours in an attempt to corrupt them.
But Corrections said the prison guards didn't take the bait and alerted managers.
Corrections then called in its Intelligence and Integrity Support Team.
The Intelligence unit tapped prison phone calls and it was discovered that the bar tab, which was left anonymously for the guards, had been orchestrated by a prison inmate.
Police are now investigating the incident.
RNZ understands the prisoner was a member of the Comancheros gang and the Corrections Officers targeted worked at Auckland's Mt Eden prison.
Corrections took two months to respond to an Official Information Act request from RNZ and has withheld most documents relating to the incident, however, National Commissioner Rachel Leota confirmed it occurred on 23 May.
"When Corrections staff were socialising at a bar outside work hours, a bar tab was anonymously left by a member or members of the public for Corrections' staff use," she said.
"Corrections staff did not use the bar tab and departed from the location.
"We are satisfied that the staff behaved appropriately and no breach of our Code of Conduct occurred."