"[We] did everything together. We ID'd her body. That's how close [we were]."
The visits were "not scary," and Dawson's presence was quiet with the ghost "almost whispering" when she spoke, Ms Holtznagel claimed.
"It's happened once at my grandma's house, again when I moved into my place in LA and then just the other night in my hotel room in Amsterdam. It's the most surreal thing that's ever happened to me," she said.
"The first two times I've felt someone sit on my bed, right next to me and then feeling a weight on my forearm.
"The other night was the first night I actually had the courage to turn and look," she said.
"When it happened the other night she said "it's ok" a few times, then she was just saying along the lines of, 'you know this time last year was really rough.'"
Ms Holtznagel claimed the visits happened when she was still wide awake, and said she did not think she was imagining things.
"I definitely do not think being over tired is the case," she said.
"It's happened to me more than once and I remember things like that happening since I was about 14."
Charlotte Dawson was found dead in her luxury waterside apartment at Woolloomooloo, Sydney, in February last year.
Dawson, a television personality and former model, had struggled with depression for years and had been the target of cyber bullying through social media.