Nearly 27 years after the murder of her father, Italian business executive Maurizio Gucci, Allegra Gucci is speaking out about the experience.

She plans to release a book to set the record straight about her mother, and her mother's involvement in her father's murder, after decades in which the story has captured pop-culture imagination.

"When you go through something like that, it's like a tsunami," she told the magazine Vanity Fair about the events of 1995.

"I'm in my room. I hadn't slept well that night. My mother, Patrizia Reggiani, comes in and quickly says, that my father is dead," the now 40-year-old recounts.

She said she felt as though she were in a bubble, while the rest of the world kept turning around her. She learned from a television report that it had been murder.

A hitman killed Maurizio Gucci, who was at that time head of the famous Gucci fashion house, on March 27, 1995. In 1998, Reggiani, his ex-wife, was sentenced to prison for having organized the murder and hired the hitman.

The prosecution said Reggiani, whom Gucci divorced in 1985, was motivated by envy and financial gain. After 18 years in prison, she was released in October 2016.

Allegra Gucci has plans to publish a book on Tuesday, in order to share "her truth." She says her mother changed after a brain tumour operation in 1992.

She says she doesn't agree with the way her mother is portrayed at times and was partially motivated to dive back into her memories by the Ridley Scott film "House of Gucci", released last year with Lady Gaga as Patrizia Reggiani and Adam Driver as Maurizio Gucci.

The film contains many lies, she says, which she is hoping to correct with her book.