Rihanna, the chart-topping singer, has won her legal fight with Topshop over selling T-shirts featuring her image without her permission.
Topshop had disputed the claim, but Mr Justice Birss today ruled in favour of the singer in the High Court.
He said Topshop's sale of a Rihanna T-shirt had been an act of "passing off", and that a "substantial number" of customers were likely to have bought the T-shirt of a "false belief" that it had been authorised by the singer.
The judge added that was damaging to her "goodwill" and represented a loss of control of her reputation in the "fashion sphere".
He said it was for the singer not Topshop to choose what garments the public thought had her endorsement.
The Barbados-born pop star, 25, has been in legal dispute with the High Street retailer for more than a year.
In a written judgement today, Mr Justice Birss did not make any assessment of damages.
A spokesman for Topshop said they are "surprised and disappointed by the judgement handed down today".
They went on: "We feel that the fact that Rihanna has shopped, worn and had a relationship with Topshop for several years appears to have been detrimental to our case.
"We robustly dispute the Judge's conclusion. We beleive that our customers clearly understand when we are undertaking a collaboration such as the one we created with Kate Moss over several seasons.
They added that there "was no evidence of consumer confusion to support the Judge's conclusion."
"Topshop are therefore perplexed by the judge's decision and are considering all options available to us including seeking to appeal."
Rihanna, whose biggest hits include Umbrella, What's My Name? and We Found Love, was once rumoured to be in talks with Topshop to launch a fashion line after she had dinner with Arcadia Group boss Sir Philip Green in Barbados in Christmas 2010.
But Rihanna signed deals to design clothes for rival brands River Island and Armani.
The claim was lodged with London's High Court in March of last year in the name of Rihanna and her New York-based rights companies Roraj Trade and Combermere Entertainment Properties.
The singer argued an unknown quantity of T-shirts were acquired by Topshop in 2011 and early 2012 and offered for sale under the name "Rihanna Tank".
The judge had previously heard that Topshop bought a licence to use the image on the T-shirt from the freelance photographer who took it during the video shoot for We Found Love, which was filmed in Belfast and Bangor in 2011.
A source from the singer's entourage had previously said her management team had asked the fashion store several times to stop selling her image.
"They buy the pictures from a photographer, but they do not pay the artist licensing fees. Unfortunately, UK law does not protect the artist," they told the
New York Post.
The Topshop T-shirt which sparked the disagreement .
