All it took was one photo found by chance on his computer late one night in June last year and her seemingly normal life fell apart.

"It was a really weird feeling to see what I was seeing," Lisa recalls.

"It was like lifting the lid off Pandora's Box and I couldn't close it."

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Lisa had discovered her husband's dark secret - a stash of child pornography so vast and so despicable that he was instantly no longer the man she knew and trusted.

What she did next - reporting him to the police - took immense courage.

Romen Vargas is due to be sentenced on Friday in Wollongong District Court after pleading guilty to seven charges of possessing child abuse material.

Speaking exclusively to the Illawarra Mercury, Lisa says she hopes the sentencing will allow her to feel some sense of closure.

"I refuse to feel shame," she said. "People don't get to make me feel like I did something wrong. I did everything right."

The Wollongong couple had a seemingly normal life and marriage for 15 and a half years.

They met when Lisa was 22. They got engaged, then married and next came the house.

Lisa was happy to be a homemaker.

She said her husband had always been involved in his computer, often playing games on it.

He had a long career as an information technology specialist.

Vargas provided for his wife and was an attentive husband, supporting her when she went back to university and re-entered the workforce.

"From my perspective our lives were normal. We had our ups and downs, as all couples do, but we worked through them," she said.

"Eventually, like so many relationships, things just weren't harmonious, and it was heading towards its eventual conclusion."

Lisa planned to leave Vargas. But she had no idea what dark and sick obsession her husband held.

"I stumbled across a file I shouldn't have which opened Pandora's Box," Lisa said.

She saw a photo of a child in a compromising position.

Her first thought was "oh" then "what the f--k".

Lisa didn't call the police straight away because she needed to confirm what she had seen was real.

Nothing had prepared her for what she found.

The next day her worst fears became reality and she found there wasn't just one photo, there were many.

Police would later find hundreds of thousands of images and videos of child pornography.

She didn't confront her husband about what perverted photos were on his computer, fearing he may delete the evidence.

After consulting health professionals, she called the police and invited officers to her house to look at what she had uncovered.

"I had mapped out a selection of paths to continue forward in my life," she said.

"Then the sands shifted underneath me and sent me hurtling down a road I could never have even imagined and which has so much darkness of the unknown around it."

An examination of the computer revealed Vargas had more than 200,000 files, located in a single folder, of child pornography which depicted pre-pubescent girls in various stages of undress in sexually explicit or provocative positions.

The device contained more than 5000 videos with at least 2000 of them of real pre-pubescent girls involved in sexual acts

Alarmingly, police found a 170-page PDF document on a USB titled "how to practice child love" which provided a step-by-step guide for adults to sexually abuse children.

Officers took CDs and DVDs which later revealed more child abuse images, with one dating back to 1999 as well as text files which had stories about having sex with children.

It was less than a week after Lisa found the images that Vargas was arrested, and she felt she "could breathe again".

Lisa has realised she will likely never know why Vargas needed so many images or had such a "prolific obsession" and kept the files for so long.

Lisa said there had been no obvious "warning signs" except his Instagram account, through which he followed tween girls.

"Our relationship was just like anyone else's on the surface. From my perspective there wasn't anything unusual that jumped out massively," she said.

"I look back now and see the red flags in hindsight but in the moment, you don't ignore them but you don't necessarily see them either.

"I loved this man, I didn't want to believe anything negative about him."

Lisa then had to accept the husband she had loved was not the man she knew.

"You don't want to think that about the person you are sharing your life with," Lisa said.

"The last thing I ever thought is what happened.

"I don't want to think that our whole time together was a lie but then I can't help but question if it was."

The most common phrases people would say to her after finding out about Vargas' arrest was, "he's such a lovely guy. He's so nice. He couldn't have done this".

Lisa said she barely spoke to Vargas after he was arrested and doesn't want to talk to him again.

Lisa is not considered a victim in the eyes of the law but she does identify as one because she has been the one to struggle through the fallout of his crimes.

"I don't want to be a victim, but I am a victim," she said.

"The image of a victim being weak or vulnerable isn't necessarily the truth.

"I have been victimised but from that I have come back stronger."

Lisa struggled to access victim support services but was grateful to have been connected with and approved for specialised counselling.

Lisa's best friends and family have helped her get through the difficult times, especially when selling the house.

Going to regular psychology sessions and surrounding herself with supportive people have helped prepare Lisa for a life she never anticipated she would live.

Lisa wants other partners or victims to know there is support available, that they can speak out and has urged them not to hide loved one's crimes out of a sense of fear or loyalty.

*Lisa's surname and other details of her story have been withheld for privacy and legal reasons.

Victim support services available:

Partner Speak: 1300 590 589

Victims Access Line: 1800 633 063

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