Kristin Scott Thomas is the ''ultimate evil mother'' in 'Only God Forgives'.

The actress plays Ryan Gosling's mum in the new thriller from Nicolas Winding Refn and says her character - who tasks Gosling's anti-hero with seeking vengeance on the mobsters that killed his brother - is a far cry from the refined roles she's used to playing.

She said: ''She is the ultimate evil mother. Almost like a nightmare, fantasy creation, who tries to consume her children, then spits them out again. I don't really relate to her in any way at all.''

The British star totally immersed herself in the role, even undergoing a physical transformation by wearing unflattering skin-tight dresses and sporting peroxide blonde hair.

Scott Thomas felt her character's look helped her disassociate the mean-spirited alter-ego from herself.

She explained to the Metro newspaper: ''I based her on Donatella Versace. The costume became a sort of battle dress for me. I was able to play these outrageous themes and do and say things that I felt quite grubby about.

''There are scenes in the film that I couldn't watch, that I couldn't even read on the page. But the really disturbing thing is just the real undercurrent of pure evil.''