Roberts is a favourite among American audiences

Fashion designer Valentino said the two actresses looked "unkempt in jogging trousers", in an interview with German newspaper Die Zeit.

"They look like homeless people," he is quoted as saying.

He said in the past actresses had to commit by contract to "appear in public like stars when they left their homes".

Red carpet

"Today you see Julia Roberts and Cameron Diaz running around looking unkempt in jogging trousers, they look like bag ladies, like homeless people. In the past you never saw that," he told the newspaper.

The designer criticised Diaz for wearing jogging trousers

The Italian designer made his name in the 1960s and still designs for the Valentino fashion group.

He dresses actress Gwyneth Paltrow and is often seen with her at red-carpet events such as the Venice film festival.

Valentino also designed the wedding dress worn by Jacqueline Kennedy for her marriage to Greek shipping tycoon Aristotle Onassis.