Corrections is investigating claims an inmate at a women's prison gave a female guard a nude, full body massage, and that a male guard exchanged contraband for sexual favours from an inmate.
A third allegation is also under investigation: that a Corrections employee working outside prison handed over $14,000 a month in exchange for marijuana that was then distributed to the criminal gangs he had access to.
The allegations were made by a former inmate at Auckland Regional Women's Correctional Facility.
The woman, whom the Herald on Sunday agreed not to name, said a prison boss tried to tell her the massage did not happen. "[But] I saw it. It was full body and nude. It was in a cell with the door open."
The former inmate, who was released in October after serving a four-and-a-half-month sentence, said another officer told her a male colleague had given an inmate contraband in exchange for sexual favours. She later saw the inmate with food not available behind bars.
A cellmate in the Auckland District Court cells told her of the allegations relating to the employee dealing in marijuana.
The former inmate has more than 400 convictions for shoplifting and fraud, but said she was receiving medical help for psychological problems and had not re-offended since her release.
Department of Corrections corporate services deputy chief executive Vincent Arbuckle confirmed the woman had made a number of complaints and they were being treated seriously.
Arbuckle would not comment further on the investigation or what had already been established. He did not known when the investigation would be completed.
The department expected staff to role model law-abiding behaviour, Arbuckle said.
Measures in place included drug testing of staff, an 0800 "integrity line" for staff to get confidential advice or report concerns. An integrity committee had also been set up and pre-employment checks included questions around integrity and conflict of interest.
Labour Corrections spokesman Kelvin Davis was pleased the former inmate's allegations were being investigated.
"If people have been found to be doing wrong, there needs to be consequences."
Previous incidents meant all allegations must be treated seriously, he said.
"Nothing surprises me any more."
Davis has led the charge on questions over the management of Mt Eden Correctional Facility, run by private firm Serco, which was this week told its contract would not be renewed in 2017.
An investigation by Corrections' chief inspector into organised fights, drinking and drug use at the central Auckland jail, and allegations about the death of an inmate under Serco's watch, has been completed. Its release is on hold because of a High Court challenge by Serco.
Auckland Regional Women's Correctional Facility is not run by Serco.