In the newly released clip, the former deputy Prime Minister also speaks about the allegations the pair took a number of trips on the public's money.
Barnaby asserts, 'They have investigated this to death.'
'I’ve had like 160 inquiries and at this point not one, not one, has come up saying ‘Oh, this is a problem’.'
Ms Campion also had her finances investigated.
'They have found that they actually owe me money,' she says.
The couple's explosive interview with Channel Seven comes months after the former deputy Prime Minister stepped down from his role, as sexual assault allegations also surfaced.
'This is garbage and the purpose of this, I believe, was to force me out of my job,' he said of the alleged assault claims.
In the couple's earlier interview, Vikki opened up about the moment she discovered she was pregnant.
Vikki, who is almost two decades younger than Barnaby, candidly told Cullen that excitement wasn’t the first thing she felt.
‘I felt... overwhelmed by the complexity of the situation which we had caused ourselves,’ she said.
‘Barnaby is strongly pro-life... I believe that a woman has a right over her own body up to a point, certainly up until the baby has a heartbeat.
‘I thought, well, maybe I should just take matters into my own hands and basically save everything from happening... by considering an abortion.
‘I tried and I couldn’t go through with that,’ she added.
‘I bought the medicine online – you can’t do it in the ACT. I drove interstate... I walked in and I walked out again.’
Later in the interview, she said she came under pressure from ‘conservatives’ in parliament to terminate the pregnancy.
‘I felt like I had two options...I thought I could have an abortion and then move overseas and forget everything had ever happened. Then when I couldn’t do it I... wrote to my two closest girlfriends from high school and said to them, “I’m pregnant and I think I’m going to be doing this by myself.” ’
‘You can’t help who you fall in love with,’ she added.
The former Deputy PM said he felt he was ‘living a lie’ as he kept up the appearance of being in a happy marriage with his wife – something he is ‘not proud of ’.
‘I have failed, I failed, I failed, I failed, I failed... and I am sorry,’ the now-father-of-five said.
‘The biggest failure of my life was the failure of my marriage... but you just can’t live your life beating yourself up.’
And so, what does the future hold for the innocent baby at the centre of it all? The couple say the payment for their Sunday Night tell-all will be put in a trust for Sebastian – a fund that neither of them can access.
And while Vikki said her pregnancy and labour wasn’t easy, it’s clear her young son is the light of her life.
Tears filled her eyes as she said: ‘As soon as I saw him and held him...everything was worth it for this.’