Gemma Chan is ''too scared'' to wear her grandmother's cashmere jumper.

The 33-year-old actress - who made her movie debut in 2010 when she was cast as Shin Shin in the World War Two production 'Shanghai' - has admitted her grandparents vintage garment is her most prized possession, although she is ''worried'' when she wears because she is scared she'll lose the garment or get a stain on it.

Speaking about her most treasured wardrobe staple, the brunette beauty said: ''I have a delicate cream cardigan from my granny from the sixties. It's one of the few things she treated herself to - she passed it on to my mum and then my mum gave it to me. It's so beautiful, but I'm too scared to wear it because I'm worried about losing it or staining it - guaranteed I'd be stuffing something into my mouth and would spill food down it.

And Gemma - who competed on the UK version of 'Project Runway' in 2006 and has starred in modelling campaign for Selfridges - has revealed she isn't much of a hoarder and regularly has a clear out.

She explained: ''I try to do a big wardrobe clear out every couple of months, although I often think, 'I wouldn't wear that as me, but I might in character.'''

Although the 'Humans' star - who plays Anita/Mia in the television show - has admitted she doesn't keep hold of many of her clothes, she has kept a section in her wardrobe especially for ''audition clothes''.

Speaking to Stylist magazine, she said: ''I have a section of the wardrobe for audition clothes. For my first audition for 'Humans' I wore a green silk shirt and jeans - in the script they referenced a mint green uniform (which became a little different). Clothes are so instrumental in making you feel a certain way. If you're wearing the wrongs shoes for your character it sets you off on, literally, the wrong foot. I've gone to auditions in a rush, and pulled on shoes and it's felt completely wrong.''