"There’s meant to be money in his mum’s house in a safe from one of the funds, but she wouldn’t give him the money from that account for the TV. He went really mad.

"Even though this was a big red flag, I'd gone this far and I just felt I couldn't get out of the situation and really wanted to believe that Steven was not guilty."

"The hairs raised up on the back of my neck and there were goosebumps on my body. Out of all the things to say in the world, that's the last thing you'd say. Why wouldn't you say: 'I didn't need to clean anything up'?

"He leaned back in his chair, I'll never forget it, his eyes constricted to the point that they looked almost white, and he said: 'No, I had five days to clean it up,' he said it grinning like a Cheshire Cat.

"I said - half joking, as I believed he was innocent at the time: 'People say the only reason there was no evidence in your trailer was because you had three days to clean it up'," Lynn revealed.

In that first visit, Lynn asked him about about Teresa's murder and why just a few days after her death, police investigators went into Avery's trailer and could smell bleach and the carpet appeared freshly cleaned.

By this point Avery was already calling her "Lynn Avery" in letters and bought her a flight to see him at Waupun Correctional Institution, in Wisconsin.

"He then wanted me to get more donations to pay for it, as the money had trickled down to barely nothing by then, so we were doing fundraising campaigns and rallies online."

15 Lynn and her daughter Credit: Chris White

15 Avery claims he has 14 women he can speak to on the phone from prison Credit: Chris White/ Lynn Hartman

In their letters, Avery would repeatedly say that it was "God's will" they should be together forever, writing in one note: "God told me that you need me and I believe him so much and I can't let go so I know God is right. God told me to marry you so I told God yes I will marry you and he said ok to me."

He was also insistent that after his conviction was overturned, they'd live away from anyone else in the Wisconsin woods.

When Avery and Lynn were approached to do the Dr Phil Show in October 2016, they agreed, so that she could tell the world about their love - and the producers were determined to make it a great love story.

"The executives wanted me to have a loving nickname for him, so I had to say on one clip that when I first saw him 'he looked like the cutest little teddy bear I'd ever seen'. I was so embarrassed, as that wasn't the truth.

"The first time I saw him, he waddled over to me and I thought: 'He looks like a teddy', as he was round and 5ft 2in, not 5ft 8in like he'd told me," says Lynn.

The interview was going well until Dr Phil asked about the pair's future, saying: "One of the things, he'd like to do is to get out and for the two of you to just go off into the woods to live alone, would you feel comfortable doing that?" Lynn said "no".

15 Avery allegedly told Lynn "F**k Brendan I don't give a sh*t about him" Credit: Courtesy of the Wisconsin Department of Corrections

15 Avery wrote to Lynn that God told him not to get mad at her anymore Credit: Chris White/ Lynn Hartman

"That's when everyone went nuts, family and supporters were telling him what happened on Dr Phil, and he was furious that I didn't want to live in the woods for the rest of our lives. I wouldn't want to live in the woods with anyone, it's just weird," says Lynn.

"So Steven then told his supporters to put it out there that I was a phony and a gold digger. Honestly, those next few days were the worst of my life. I was getting harassed by everyone online and Steven was calling every minute of the day.

"When he spoke to me on the phone, he would be screaming at me.

"He'd usually call two or three times a day, now it would be 25 times a day. I don't know how he did it, they're not meant to have a phone all day long.

"I said this is insane, I don't want anything to do with it and wrote him a postcard saying I think we should split up. He was scaring me, this guy's a freaking lunatic.

"He'd be constantly blowing hot and cold in the same calls and letters. He'd be writing to me three or four times a day telling me how much he loves me, but in the next sentence, tell me how much I drive him mad.

"When he's rejected, he becomes the Steven Avery I read in the police transcripts. When he gets mad, it's really strange, I've never seen anything like it. As soon as he started feeling rejected, the monster revealed itself."

15 Steven has won the right to appeal his sentence and hopes he will one day be set free

15 Despite having split up, Avery tells Lynn he's going to marry her and is working to buy her a ring Credit: Chris White/ Lynn Hartman

The stress of the online abuse from Avery fans took its toll on Lynn, who was admitted into hospital just days after their split.

"Telling the world that I was a gold digger ruined me and was a lie. I got thousands of prank phone calls, text messages, Facebook messages, emails, so much online hate, all saying I'm a 'money grabbing whore' and to 'rot in hell'. People were changing my address, and for four months in a row, I never got my post.

"They're still constantly messing with my head.

"I ended up in hospital for a few days, but it wouldn't stop. He wouldn't stop calling and writing after I ended it.

"When I tried to defend myself in Facebook groups, saying to go easy, I'd be told that I'm a diseased whore. Now I know how it feels to be terrorised without being able to do anything about it."

Despite coming to a temporary truce with Avery's lawyer Kathleen Zellner, where both parties handed over letters, Lynn says the threatening calls and letters from Avery continued for a further month until she got a no-contact order from the prison, after initially contacting the FBI for advice.

"I finally turned it all over to the authorities, I was that desperate. I even went to the FBI and they suggested I get a no-contact order from the prison. I had to submit evidence before it was issued. I wanted this harassment to stop. I was scared and all alone. I had no one - all my friends blamed me for getting involved and my family didn"t want to know," she explains.

"My daughter was also getting letters from Avery and abuse online, she wouldn't speak to me for a year. She was furious that she was getting all this treatment."

15 Lynn says she's been bombarded with online abuse since she split with Avery Credit: Chris White

15 Avery would fly into jealous rages at Lynn in his letters Credit: Chris White/ Lynn Hartman

In an email dated 30 December 2016, Nathan Haynes, Captain of Waupun Correctional Institution, wrote an email to Lynn, saying: "I did serve Mr. Avery with a no contact order as requested. If anyone else would like to place a no contact order on Mr. Avery and they are over the age of 18 they will need to contact WCI directly."

Lynn moved from Mesquite, Nevada, to a small town in California, yet the abuse from Making A Murderer supporters continued. Taking a break from social media gave some respite, but Making A Murderer 2 started it all back up again earlier last year.

"In February 2018, I came back on social media as I was sick of people calling me a fraud, a whore, a disgusting human being - yet there was a new wave of followers, who were now shouting the abuse. A Twitter user said they had a blow up doll of me, stabbed it to death and threw it in the garbage can," says Lynn.

"I started making reports to Facebook, Reddit and Google, and I had most of the old stuff cleared up, but there's always new stories reappearing."

Lynn realizes that by speaking up, the abuse online from hardcore fans will probably get worse, but she wants her story to be told.

She says: "I don't think it will ever stop and after this interview, I've decided I won't speak about it again. I've done all I can.

"But I thought I'm going to fight fire with fire, one person against this army, I want my voice to be heard."

Avery's lawyer Kathleen Zellner hit out at Lynn's claims, telling Sun Online: "Steven Avery has never blamed Brendan...

"We have demonstrated that the forensic evidence refutes Brendan's confession. Steven has tremendous empathy for Brendan and knows his confession was coerced.

"The authentic letters of Steven, which we have, do not indicate any obsession with sex. We are also in possession of Hartman's letters to Steven which illustrate that people in glass houses should not be heaving stones.