"Because my recollection is a much older man being creepy with me when I just had graduated high school."
She also disputes her age at the time: "He said I was 20; I definitely wasn't. I was a teenager. I had just turned 18. There was no fact checking from him or his publisher — it almost feels deliberate."
Accusing Moby of leveraging her to increase sales, Portman added: "That he used this story to sell his book was very disturbing to me.
"There are many factual errors and inventions. I would have liked him or his publisher to reach out to fact check."
Moby has responded to Portman's denials, taking to Instagram to share a photo of the pair and double down on the story he shared in the book.
Then It Fell Apart, Moby's second memoir, also shares the musician's meetings with entertainment luminaries such as Bono and David Bowie, as well as a time he touched his naked penis against Donald Trump at a glitzy party.
Moby has had a long career, starting as a techno musician with his self-titled debut in 1992 before flirting with hardcore punk in the mid-90s. His biggest hit came with 1999's Play, which topped the charts around the world.