She told Andrew Denton she’s finally learned to forgive the person who masterminded her ordeal.
"I think I have forgiven her - there's some anger there definitely but I had to let it go to move forwards," she told Andrew Denton's Interview on Tuesday night.
Casey admits she was so convinced by the catfishing that she was coerced into having sex with Olga, at the fictional Campbell’s request.
“I think by that time I was just willing to do anything to see him,” she said.
“My intuition was saying, ‘This isn't right, don't be a d**khead’. But I'd put so much time in this that he had to be real.”
Casey explained how 'Campbell' asked her to have sex with Olga, and then tell him about the encounter afterwards over the phone.
“He was like ‘do that, then we’ll all get together and do that together’,” she says before visibly cringing and exclaiming, “That’s too much,” to the crowd.
The young star agreed to the bizarre request. It was her first sexual experience.
Reflecting on Olga's motivation, Casey said she wondered if her friend was driven by repressed sexual desire.
“I don't know if she was a closeted lesbian that didn't understand her sexuality so she tried to make other people feel like they had to do that,” she said.
The singer fought back tears as she recalled the fake relationship with Campbell, which began with a phone call on Australia Day 2005 when Casey was just 16.
“You can't go out to pubs and clubs with the other people. I was like, ‘This is interesting’,” she recalled.
The first call led to six years of torment for the star, which finally ended when she finally found out the truth – that Olga was in fact impersonating a non-existent man. Campbell was completely fictitious.
“The night I found out this was all a lie, I sat on the edge of my parents’ bed at around 3am in the morning and they thought someone had died,” Casey said.