A French model who posed nude for an anti-anorexia campaign while suffering from the illness herself has died at the age of 28, her colleagues confirm.

Isabelle Caro died on 17 November after being treated for an acute respiratory illness, Swiss singer Vincent Bigler, who reportedly was her boyfriend, told journalists.

"She was hospitalised for 15 days with acute respiratory disease and was recently also very tired, but I do not know the cause of her death."

Caro caused a stir after appearing in posters for an anti-anorexia campaign in 2007, but the ads were banned in several countries.

It was not clear why it took so long for her death to be made public.

The anti-anorexia campaign came amid a debate among fashion circles on the use of "ultra-skinny" models on the catwalk.

"I thought this could be a chance to use my suffering to get a message across, and finally put an image on what thinness represents and the danger it leads to - which is death," Caro said at the time.

The model, who was 5ft 4in tall (1.65m) at the time of the poster campaign, reportedly weighed 32kg (five stones).