Father and daughter were in relationship together because of phenomenon called 'genetic sexual attraction'

A father and daughter ended up in a sexual relationship together due to a phenomenon called 'genetic sexual attraction'.

John was married to his third wife Dorothy at the time, while Jenny was also married with three children.

Speaking to the Australian Associated Press, Dorothy said: "When they got back here he informed me it was the best sex he ever had.

"If that doesn't degrade you I don't know what does. It was my second marriage, and you feel like... you get a very poor opinion of yourself."

Following their affair, the father and daughter went on to have two children together, with one sadly passing away shortly after birth.

Speaking about their relationship to 60 Minutes Australia, Jenny spoke about the moment her feelings for John changed.

"After I'd been there quite a few days I started to notice my feelings were changing and that that I was seeing him as a man, as a person, as somebody who was loving, caring, who, like, yeah I was looking at him and sort of going 'Oh, he's not too bad'," she said.

"[...] The most important thing for people to remember is that John and I are in this relationship as consenting adults. We are not harming each other."

"Or anyone else," said John.

He added: "Emotions take over, as people no doubt realise, there are times during your life where emotions do rule the heart, it rules the head.

“I knew it was illegal, of course I knew it was illegal but you know, so what.”

Speaking to 9 Stories, Dorothy explained that she and Jenny's mother Joan had tried to split the pair up.

"We tried to split them up, her mum (Joan) and I did. We tried bringing the law onto them, but they escaped," Dorothy said.

"She's not with him anymore and that's all I care about. They still think they didn't do anything wrong. Now I'm just glad I got rid of him. I'm glad it's all finished."