Hayden Panettiere is delving further into a 'shocking' incident in which she was put into bed with an 'undressed' man who was 'very famous' when she was just 18.

The 36-year-old Heroes star previously fought back tears as she relived a traumatic experience – which is chronicled in her memoir This Is Me: A Reckoning – on Jay Shetty's On Purpose podcast earlier this month.

Following her memoir's release on Tuesday, May 19, fans have been able to learn more about Panettiere's chilling ordeal.

The Daily Mail has reached out to Panettiere's representatives for comment but has not yet received a response. 

The experience is detailed in a chapter titled 'Trust,' as outlined by People.

The actress recalls how she was allegedly traveling on a 'super yacht' with numerous other celebrities aboard as she cruised around the South of France.

Panettiere writes that she was traveling with a female friend, whom she considered one of her most trusted companions.

According to the publication, the women spent multiple days aboard the yacht, in which they swam in the sea, danced long into the night and rubbed elbows with the ship's other famous passengers.

But Panettiere alleges that her trip took a more disturbing course one night, when her trusted friend interrupted her dinner to ask her to come below deck to meet someone.

After stepping into a private cabin, the Remember The Titans actress writes that she came face-to-face with a 'famous thirtysomething British singer–songwriter' who was shirtless in his bed, with the sheets covering his lower body.

'"Oh my God," I thought. "Is he naked under there?"' Panettiere writes.

She adds that her friend then whispered, 'I want you to get in bed with him,' then left her and the unnamed man alone in his cabin.

Panettiere writes that she did as she was told at first, but her mind and body soon became disconnected.

'My body no longer felt like my own,' she writes.

According to People, Panettiere adds that her experiences as a child actor who was constantly being 'managed' by adults had instilled in her a sense of blind trust in others, even when her instincts suggested that was unwise.

'As soon as the door clicked closed, my survival instinct kicked in,' she continues.

Panettiere claims that she told the famous anonymous man, 'Look . . . I don't know what she said to you, but this is not going to happen.'

Then, she ran out of the room and back to her cabin, where she booked a hotel on the mainland for safer accommodations and prepared to disembark.

Panettiere, who says the incident made her feel as if she had been betrayed by her friend, describes it as feeling as if she had been 'kicked in the face.'

'She’d confided in me, pampered me and treated me like her best friend – then turned around and treated me like a call girl,' Panettiere alleges.

The actress, who recently came out as bisexual, previously admitted she realizes now how naive she was about the danger she was in during a conversation last week on Jay Shetty's On Purpose podcast.

Shetty said: 'You write about a moment in your career where a friend of yours takes you onto a boat. You’re led to a room which has an older man in it and then basically told to perform sexual acts.'

Panettiere responded: 'The fact that I was 18, even though I’d lived such a huge life and I thought I was oh so mature at 18… scientifically, your frontal lobes don’t develop until we’re what, 25, 26?

'So even though I felt like I could make healthy decisions, safe decisions, I wasn’t capable of being fully aware of what was going on around me.'

Panettiere claims the person who led her into the shocking situation was a friend who she trusted and saw as a 'protector' before they 'physically put me in the bed next to this undressed man who was very famous.'

The actress said she was led downstairs into a small room before being put in bed with the unidentified man, who she says behaved 'like this was just an average day for him.'

Nashville star Panettiere said she immediately became 'ferocious', adding: 'That lion in me, that fire in me… my hair stood on end...

'I was like, "This is not happening"' before running out of the room and trying to hide.

'There was no jumping off and swimming away,' she said. 'And there was nobody who was going to be empathetic to my situation. I realized that this was nothing new to them.'

Panettiere shot to fame in 2006 aged 17 playing Claire Bennet - a high-school cheerleader who can spontaneously regenerate - on Heroes.

The revelation comes days after Panettiere came out as bisexual after years of feeling 'forced to be perfect' in order to avoid public scrutiny.

'It's sad that I had to wait till I was 36 years old to share that part of me, but better late than never, right?' the Nashville alum told Us Weekly last week.

'I've chosen to share it with the world, I'm comfortable saying I'm bisexual. I'm comfortable to confidently say that, yes, I am bisexual. I said it!'

Despite having little privacy due to 'paparazzi always outside waiting for me,' Panettiere still managed to secretly date women, whom she preferred to men from 'a very, very young age.'

'[I was] much more into women,' the two-time Golden Globe nominee said.

'But, yeah, I have explored it, but I don't think I ever had the courage, because I hadn't shared this with anybody. 

'I didn't really have the courage to throw myself fully, emotionally into it, because then if I did fall in love, that wasn't something that I wanted to ever have to hide. I didn't feel confident enough, and I was too afraid to really let that part of me explore that part of me.' 

Panettiere worried it would look like she was 'jumping on the bandwagon' during a 'period of time, where it felt like people coming out, especially women coming out, and saying that they were bisexual, or liked girls, was a fad.'

The Grammy-nominated narrator decided to be 'completely brutally honest' about her sexuality during the two years she spent writing her memoir.

Panettiere has only ever publicly dated men and she most recently split from convicted felon Brian Hickerson in 2020 following his eight domestic violence arrests.

She lost custody of her 11-year-old daughter Kaya Evdokia Klitschko with ex-fiancé - retired heavyweight boxer Wladimir Klitschko - whom she amicably split from in 2018 after their nine-year on/off relationship.

The Equal Means Equal activist also previously dated her much older Heroes co-star Milo Ventimiglia, retired NFL wide receiver Scotty McKnight, Welsh TV presenter Steve Jones, singer Jesse McCartney, The Hills alum Stephen Colletti and the late Pink Taco founder Harry Morton.

Panettiere is scheduled to kick off her four-date This Is Me book tour at the Barnes & Noble in Union Square in her native New York City on May 19.