Speaking to Glamour magazine, Dannii was coy about the allegations in Tow Bower's book on SiCo - but made no attempt to deny them.
She said: "I haven’t read the book, but I've been told about the excerpts that relate to me and the speculation about my private life.
"From what’s been reported they — Tom and Simon — put hundreds of hours into making this book, and Tom is a respected journalist.
"They looked very pleased with it all at their launch. I'm sure it makes for a great read and I wish them the best."
And the 40-year-old also scotched rumours that she was working toward a reconciliation with estranged partner Kris Smith.
She said: "I'm extremely private about my relationship, but nothing has changed since Kris and I separated.
"Ethan remains our priority. We just celebrated his second birthday and I'm loving every minute I get to spend with him.
"Motherhood has been the most wonderful experience and his smile makes any bad day right."
Talking about her refusal to re-join The X Factor's judging panel, she continued: "I was offered the chance to return, but I decided it wasn’t the right thing for me. It didn't fit in with arrangements I'd made for Australia's Got Talent.
"I have been with AGT since the first episode and it's filmed in my home town. I had four incredible years on The X Factor but the show has moved on and so have I.
"The X Factor will always have a special place in my heart. I'm still in contact with the contestants."
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