May 1 (UPI) -- The ad, which aired in 2014 for National Party candidate Steven Joyce, featured an unlicensed instrumental rendition of the song that was first released in 2002 as part of Eminem's soundtrack to the film 8 Mile, Rolling Stone reported.
"The song 'Lose Yourself,' is without doubt the jewel in the crown of Eminem's musical work. Not only did the song win an Academy Award for Best Original Song in a movie, it also won two Grammy Awards," Eminem, real name Marshall Mathers' lawyer Gary Williams said in court Monday.
"In short, 'Lose Yourself' is an extremely valuable song. The licensing of the song has been extremely carefully controlled. Despite many requests, it has only rarely been licensed for advertising purposes. When licensed, it can command in the millions of dollars. That's how valuable it is," he said.
The National Party denies being responsible for any copyright infringement claiming that the song used is not "Lose Yourself" and instead is a track titled "Eminem-esque." It was taken from a library made by production music company Beatbox, BBC reported.
Greg Arthur, a lawyer for the National Party, said the copyright was "not in any way proven by the name given to a piece of music."
The trial is expected to last for six days.