"I didn't take the substances, but even if I had they couldn't have caused any impairment or created any safety issue. This issue had nothing to do with narcotics or drugs in prisons. For me it was about the boundaries between work and private life."
Mr Farrow said he tried to resolve the dispute with Serco but was unable to do so. "In the end we agreed to go our separate ways. Now I just want to get on with life."
Mr Farrow had initially declined to comment but said he felt he needed to correct interpretations created by Monday's report.
"I had planned to maintain my silence, but I need to set the record straight. The story as first reported makes it look like I was involved with drug-taking. I worked in prisons for 17 years, and in all that time there has never been any suggestion I was involved with anything like that."
Corrections Minister Sam Lotu-Iiga was advised by Serco of Mr Farrow's suspension on May 14 and subsequent dismissal on July 25. However, Mr Fleming said his client had left Serco of his own accord.
A Serco representative declined to comment on Mr Farrow's statements as the company was unable to comment on individual employment matters.
Serco was relieved of its management of Mt Eden on July 24 after revelations about violence and contraband within the prison's walls. Allegations of fight clubs and drug smuggling have surfaced and the company has been docked $565,000 for contract breaches relating to prisoner care.
It emerged at the weekend that a Serco staff member at Mt Eden had been suspended after being caught fighting an inmate. Footage of the incident was discovered as part of a review into the prison being carried out after allegations of fight clubs between inmates and drug smuggling.
First prison report due this week
The first part of an inquiry into violence and contraband in New Zealand's prisons is due to be completed on Friday.
The probe was sparked by video footage apparently of organised fight clubs at Mt Eden Prison and claims prisoners were regularly subjected to violent attacks.
Corrections Minister Sam Lotu-Iiga told chief inspector of prisons Andy Fitzharris to begin a two-phase review of prisons on July 28.
The first phase, to finish this week, was to focus on the fight clubs at Mt Eden, including:
•Whether they were widespread.
•The adequacy of controls around cellphones.
•Whether managers and staff had known of and were involved in a "fight club".
•Levels of supervision and security.
•Whether violence between prisoners was under-reported.
•What actions had been taken to prevent such activity.
The second phase, due to be delivered to Corrections chief Ray Smith by September 30, will focus on prison violence and access to cellphones in all NZ prisons.
Labour MP Kelvin Davis, who raised concerns about Mt Eden in Parliament, said the investigations had taken place under a "veil of secrecy".
An investigation is also under way into the clinical assessment of Nick Evans, a prisoner who died from medical complications after an alleged assault at Mt Eden.
An inquest will be held once the other inquiries have been completed.