She said the pair had "engaged in sexual activity while on duty and within a high security area" of the prison and that Mr Ifraz had allowed her to leave work early to meet her offsite as well.
Her husband worked at a different prison.
Mr Ifraz was suspended from July 28 last year while an investigation took place.
The final report was produced in March this year and Mr Ifraz was summarily dismissed on August 4.
But Mr Ifraz argued he should be reinstated in his position as the case moved forward - stating he understood he could not work with the female colleague or her husband, but could work in another prison.
Prison director Cheryle Mikaera said she had lost faith in Mr Ifraz and "given his lack of remorse or regret" could not see how she could trust him as an employer again.
The authority said it backed the Department of Corrections in the case, saying reinstatement could cause "resentment" for other staff.
"The prison environment is not a typical working environment," authority member Vicki Campbell said.
"This is an environment where there needs to be a high level of trust with all employees but especially those employees who are making management decisions on a day-to-day basis."
The application for interim reinstatement was declined and costs were reserved until after the substantive investigation and final determination.
Corrections Services northern regional commissioner Jeanette Burns said the department would not comment on the case before the outcome of the hearing is revealed in December.
The overwhelming majority of corrections staff fulfil their duties with "integrity and commitment", she said.
"The department demands a high standard of conduct from all its employees and staff are expected to role model positive behaviour," she said.
"Any large organisation may encounter a few staff who cannot maintain the high standards set by the majority, and when staff don't meet the standards required of them we take the appropriate action regarding the employee involved."
