Katy Perry's fashion designer friend Jeremy Scott has lost his bid to end a legal battle over a dress he created for the singer.

Moschino designer Scott has been sued by a graffiti artist called Rime, real name Joseph Tierney, over a street art-style printed gown which the Firework star wore to the Met Gala in New York City last year (15).

Tierney, who filed suit against Scott in August (15), alleges the designer copied the motif for his Moschino autumn 2015 collection from a wall mural the artist created in Detroit, Michigan in 2012.

Scott fought back by filing a motion to dismiss the case, insisting he did not choose the print used on the fabric, but a judge in Los Angeles has now ruled the case should continue, insisting it is unlikely the designer would have let someone else pick the print for his collection.

The judge stated "the high-profile head designer... would participate in the design of its most high-profile garment of the season," according to New York Post gossip column Page Six.

The case is due back in court in California on 23 May (16).