Germany's highest court was examining Wednesday a case that erupted 18 years ago over a German hip hop artist's two-second sample of a tune by electronic music pioneers Kraftwerk.

At the heart of the dispute is a short drum sequence looped repeatedly in the song "Nur mir" (Only Me) by Sabrina Setlur, who previously had a relationship with German former tennis star Boris Becker.

The sequence however originally came from Kraftwerk's 1977 release "Metall auf Metall" (Metal on Metal).

Since the release of "Nur mir" in 1997, Kraftwerk's lead singer Ralf Huetter has been battling over the rights of the sequence against the producer Moses Pelham.

The electronic music veterans had already won German court backing for damages and an injunction over the song, but Pelham and Setlur appealed and brought the case to the country's highest court claiming it infringed artistic freedom.

At the constitutional court hearing in Karlsruhe on Wednesday, Huetter insisted that the commandment "thou shalt not steal" applied also to music.

But Pelham argued that sampling is common practice in the hip hop genre.

He said he works from a set of interesting music sequences and was not aware then that the sample in question stemmed from Kraftwerk's work.

Pelham appeared to have the backing of the German government, with Berlin's representative Hubert Weis saying that artists should in principle be allowed to sample without having to pay music labels for the right to do so.

"The right of artistic freedom overrides commercial interests," said Weis.

The court is called on to rule on whether Kraftwerk's label had suffered damages through the sampling, but the judge can also decide to send the case to the European court, given that the EU's 2002 copyright rule does not specifically address the question of sampling.