The 39-year-old TV presenter met the Hollywood producer - who has been hit with multiple accusations of sexual misconduct by the likes of Ashley Judd, Rose McGowan and Kate Beckinsale - for lunch in Cannes in 2010 but told him to "f**k off" when she discovered his intentions.
A friend of the former Hear'Say singer told The Sun newspaper: "She thought his intentions were genuine. But as soon as she found out what he really wanted, she told him to f*** off."
Myleene interviewed Harvey at the time at the Cannes Film Festival while working for news channel CNN, and he invited her out for lunch the day afterwards.
Later that year she discussed the incident in an interview, claiming a "married Hollywood star" had approached her about signing a "sex contract".
Speaking in 2010, she said: "About six months ago, a newly married Hollywood star asked me to sign some kind of sex contract with him. I just thought, 'Mate, which planet are you from?'
"I met him a few times and when I went to interview him it was like something out of a film We were having lunch and as the starter arrived he launched into it.
"I was like, 'Bugger, I've got main and dessert to go - I'm stuck here'.
"Then his PA came over with a confidentiality contract. I just thought, 'Oh my God, your poor wife.' I don't want to be a marriage-wrecker."
Harvey married wife Georgina Chapman in 2007 but she has since left him following the sexual harassment allegations.
The disgraced movie mogul — who has children India, seven, and Dashiell, four, with Georgina, as well as Ruth, 14, Emma, 19, and Lily, 22, with his ex-wife Eve Chilton — has admitted he "supports" the fashion designer's decision, but hopes they will reconcile.
He said: "I support her decision, I am in counselling and perhaps, when I am better, we can rebuild.
"Over the last week, there has been a lot of pain for my family that I take responsibility for. I sat down with my wife Georgina, who I love more than anything, and we discussed what was best for our family.
"We discussed the possibility of a separation and I encouraged her to do what was in her heart. I understand, I love her and I love our children and hopefully, when I am better, I will be in their lives again."
A spokesperson for the former Weinstein Company co-founder - who was sacked from the company in the wake of the scandal - has previously said he "unequivocally denied" allegations of "non-consensual sex".