It is understood the woman was distressed over the allegations and the potential damage to her reputation. She was moved to work at another unit at the prison.
"There is no truth to allegations that a female Corrections officer was in a sexual relationship with a prisoner," said Tom Sherlock, Auckland Prison director.
"Allegations of this nature are taken seriously.
"However, it quickly became obvious there was no truth to them and this staff member was the victim of an infatuation."
Sherlock added that Corrections officers were regularly rotated around different units and the staffer has been been moved to another unit as part of her rotation schedule.
"Corrections provided the staff member with support from senior female staff and counselling was offered," he said.
There are 40 female Corrections Officers at Auckland Prison and 745 nationwide.
Baker is one of New Zealand's most callous killers and has a long rap sheet.
He was jailed for life after pleading guilty to killing 17-year-old Ashley in the back of a prison van while the pair were being transported to Auckland Central Remand Prison in November 2006.
The teenager was strangled before Baker stomped on his head. Baker was in custody after being charged over a North Shore stabbing and threatening witnesses.
When the van arrived at the prison, security guards found Ashley slumped on the floor. Baker told them: "You better get him out of there. I've just killed him. He's not breathing."
He was jailed for life with a minimum non-parole period of 18 years.
In 2008, Baker tried to escape from a van returning him to prison from North Shore Hospital.
A year later, he took an elderly prison inmate hostage for two hours and threatened to kill him.
