Singer Katy Perry arrives for the "Silence the Violence" Benefit Concert held at The Anthem on Friday, Oct. 11, 2019, in Washington. Picture: AP

 US pop star Katy Perry has been sued by Australian fashion designer Katie Perry over alleged trademark infringement. 

The Sydney-based designer owns a female loungewear clothing label and goes by Katie Taylor now, but she still continues her fashion brand under Katie Perry, her maiden name, for which she also holds the trademark registration in Australia.

According to court documents, Taylor launched litigation proceedings for trademark infringement against Perry, whose real name is Katheryn Elizabeth Hudson, as well as her company Killer Queen LLC, in the Australian Federal Court in Sydney on October 24. 

The first case management hearing has been set for November 21. 

"This is a real David and Goliath fight," Taylor said in a statement sent to dpa on Thursday. 

She said she was fighting "for all small businesses in this country who can be bullied by these overseas entities who have much more financial power than we do." 

Taylor established her fashion label in late 2006 and has held trademark registration for Katie Perry-branded clothes in Australia since September 29, 2008.

Taylor said she was asked by the singer's lawyers in May 2009 to withdraw her trademark application for her label. But the singer dropped the case just before it was set for court.

Taylor alleges Perry has since ignored her Australian trademark, "placing herself above the law in Australia," and selling clothing under the Katy Perry label in large supermarkets, including Target. 

Taylor said she was able to commence expensive legal proceedings only after finding support from Litigation Capital Management Limited, a global litigation funder.