US rapper Eminem is suing New Zealand's National Party for allegedly using his Lose Yourself song in a campaign ad to get Prime Minister John Key re-elected.
The Ministry of Justice on Tuesday confirmed that proceedings were filed in the Wellington Registry of the High Court.
Eminem's publishers also made a statement saying they are seeking damages for copyright infringement against the National Party.
The Detroit-based copyright holders allege "unauthorised use has been made of Eminem's Grammy and Academy Award winning song, Lose Yourself, in election campaign advertising run by the National Party in the lead up to the 2014 New Zealand General Election".
Joel Martin, speaking on behalf of the publishers, said Eminem was never approached for permission to use his work in National's rowing-themed election ad, which features music backing similar to the tune of Lose Yourself.
"It is both disappointing and sadly ironic that the political party responsible for championing the rights of music publishers in New Zealand by the introduction of the 3 strikes copyright reforms should itself have so little regard for copyright," Mr Martin said in a statement.
But National has flatly rejected the allegation it infringed the rapper's work and says the backing came from an Australian-based production outfit.
"The National Party will be defending this action vigorously. As the matter is now before the courts we will not be making any further public comment."
The party says it was alerted to the copyright infringement complaint two weeks ago and made a compromise not to continue using the track.
"However, this has not satisfied the complainant," National said in a statement.
They said the work in question has been used by other organisations without complaint.
"It appears though that the National Party is the only organisation that has used this material that is being legally targeted."
This is not the first time Eminem has launched legal action over copyright infringement.
In 2004 he sued Apple for using a song in one of its television commercials without permission.
