Appeal judges will hear a T-shirt row between singer Rihanna and high street store Topshop today.
Last year a High Court judge concluded that Rihanna fans might have been deceived into thinking that she had endorsed a T-shirt sold by Topshop.
Mr Justice Birss ruled that Topshop's sale of the T-shirt without without Rihanna's permission was ''passing off''.
Topshop bosses are challenging the ruling in the Court of Appeal and t hree appeal judges are due to hear legal argument at a hearing in London.
Topshop had sold the T-shirt - which bore an image of Rihanna taken from a photograph - between March and August 2012, Mr Justice Birss was told.
The store had no licence from Rihanna to sell the shirt, the judge heard. And the singer had taken legal action claiming that selling it without her permission infringed her rights.
Topshop had disputed her claim, saying nothing on labelling suggested that the T-shirt had been authorised by Rihanna.
Bosses said the public had no expectation that clothes were authorised by people shown in an image.
The judge ruled in Rihanna's favour in July 2013 after a trial in London.