American rapper, Eminem has staged up a legal battle against New Zealand's National party for using an unlicensed version of his 2002 hit song 'Lose Yourself' without permission for a political campaign ad in 2004.
According to the New Zealand Herald, the case kicked off in the High Court at Wellington on Monday between Eminem's publishers, Eight Mile Style, Martin Affiliated and National Party of New Zealand.
It was reported that the party's lawyers argued in Court that it was not actually Lose Yourself, but a track called Eminem-esque which they bought from a stock music library.
The court played the full version of 'Lose Yourself', with lyrics, followed by a track whose file was allegedly labelled 'Eminem-esque', before the instrumental of 'Lose Yourself' was heard.
A lawyer for Eight Mile Style - a publishing group representing the rapper said, Lose Yourself was 'iconic' and 'without doubt the jewel in the crown of Eminem's musical work".
He said the 'iconic musical composition" had been wrongfully used - and despite many requests in the past, had only been licensed for ads on a few occasions.
'Its commercial exploitation is tightly managed to protect the integrity of the work," he said.
'It's known in the advertising industry that 'Lose Yourself' is not commonly available."
He said the file for the song on the commercial may have originally been labeled 'Eminem-abbr", but later renamed 'Eminem-esque'.
While the National's lawyers say the song was part of a library bought from production music supplier Beatbox.
The trial is set down for six days.