Allison Janney thinks Margot Robbie is a ''triple threat''.

The 58-year-old actress is currently starring alongside the Australian beauty in 'I, Tonya' - for which she won a BAFTA for Supporting Actress on Sunday (18.02.18) - and she has compared her on-screen daughter to late Hollywood leading lady Katharine Hepburn for the way she drove the project.

Speaking to the Metro, Janney said: ''She's incredibly brave and fearless in her portrayal of Tonya [Harding].

''She is the modern-day Katharine Hepburn. She wasn't getting the parts she wanted so she decided to put on her producer hat and find female-driven content.

''To take on this iconic, tragic American sports figure and adopt the accent and learnt the skating... I think she's extraordinary and I have tremendous respect for her.

''I think she's going to be a huge voice in Hollywood going forward. The new triple threat - producer, director, actor Margot Robbie.''

Janney stars as LaVona Golden, the abusive mother to the Olympic figure skater in the new movie by Craig Gillespie, and watched documentaries to get into the mind of the character.

She said: ''Other people corroborate LaVona hitting Tonya at the rink.

''There's documentary footage of LaVona and I watched those tapes over and over again.

''I found that whole theme in this movie - about truth, and each character's version of the truth and what they tell themselves in order to get up every day and live their lives - compelling.

''I doubt that LaVona Golden thinks of herself as an abusive mother.''

'I, Tonya' documents the life of notorious skater Tonya, whose now-ex-husband Jeff Gilooly plotted with her self-appointed bodyguard Shawn Eckhardt to take out her rival Nancy Kerrigan to pave the way for her a spot on the US Olympic team.

Despite their efforts, Nancy recovered from her knee injury and competed against Tonya in the 1994 Winter Olympics.

Nancy remarkably won the silver medal in the Games and, after details of the crime - known as The Whack Heard Round the World due to the fact she was clubbed around the knee with a baton - came to light, Tonya was dished out a sporting lifetime ban for her knowledge of the attack.

Jeff, on the other hand, was handed a two-year prison sentence.