Kelly Brook says if people are being digitally slimmed down in photos then a clear warning should appear.

Her comments come as fresh calls are made for airbrushed photos to be clearly labelled.

The Girl Guides are petitioning the government to bring in new laws. The organisation says half of 16 to 21-year-old girls consider cosmetic surgery.

Brook was speaking at the launch of her new poster campaign in London.

She said: "If people are being slimmed down in photographs then I think that should definitely be pointed out because you don't want to portray something that is unrealistic and unachievable to young teenage girls."

She admitted the picture in her new billboard advert was "probably" airbrushed.

Government action

It follows concern last month from Equalities Minister Lynne Featherstone.

She said she wanted either the practice of airbrushing ended, or labels introduced to show where images have been altered.

The eating disorder charity Beat is also supporting the call for more clarity about airbrushed pictures.

I guess I'm not a typical 5'10 skinny supermodel, I'm 5'6 I'm curvy, I've got real boobs - that hang! I'm just normal Kelly Brook

Susan Ringwood from the group said: "We know the difference it would make to all young people's self esteem and body confidence if they could be sure which of the images they see are natural and true to life."

'Unnaturally perfect'

Brook went on to say that any label at the bottom of photos saying 'this is airbrushed' should be "small".

"Airbrushing has been around since the '50s. It's what Hollywood was built on and I'm a big fan of Hollywood and that whole era."

She said her own looks were perfectly normal: "I guess I'm not a typical 5'10 skinny supermodel, I'm 5'6 I'm curvy, I've got real boobs - that hang! I'm just normal."

But Liz Burnley of Girlguiding UK said young girls feel "profound" pressure to conform to a particular body image and "unobtainable ideals".

She said: "We are proud to support the calls of our members who believe that it is time that the Prime Minister addressed their concerns and acted in the interests of girls and young women across the country."

30-year-old Kelly Brook is playing a gym instructor for one episode in the next series of Skins, which she's already filmed.

She explained: "I was on a power plate most of the time, shouting instructions to all the girls. It's just funny, I kind of hammed it up. It was campy and fun and silly and a bit tongue in cheek."

She's also starring in new movie Piranha 3D which is out in cinemas on 17 August.

The film's about pre-historic man-eating piranhas that get released during spring break and ruin the party.