Elvis Presley's granddaughter, Riley Keough, said Friday it was "very intense" watching the new biopic about the rock'n'roll legend, which premieres at the Cannes Film Festival next week. 

Keough, known for films like "Logan Lucky" and "American Honey", happened to be at Cannes for her directorial debut "War Pony" just days before the world premiere of "Elvis" by flamboyant Australian director Baz Luhrmann. 

She told an audience at the French Riviera festival she saw the film recently with her mother, Lisa Marie Presley, and grandmother, Priscilla Presley. 

"It was a very emotional experience," she said. 

"There's a lot of family trauma and generational trauma that started around there. It was a very intense experience."

"Elvis", which premieres on Wednesday, stars newcomer Austin Butler in the lead role and Tom Hanks as his infamous manager, Colonel Tom Parker. 

Despite the discomfort of seeing her family on screen, Keough said she was "honoured" that it was handled by Luhrmann. 

"The first movie I ever watched in a theatre where I knew I wanted to make movies was 'Moulin Rouge!' when I was 12," said Keough. 

She said it was immediately evident how much effort Luhrmann and Butler had put into capturing the essence of The King. 

"That made me emotional and I started crying five minutes in, and didn't stop, so I need to watch it again," said Keough. 

The family was involved in helping Luhrmann get access to the Presley home, Graceland, and other people from Elvis's life. 

"But at the end of the day, we're not going to tell Baz Luhrmann how to make a film," Keough said.