Nintendo is refusing to pay a 149.1 million euro fine slapped on its for allegedly price fixing.
European Union regulators fined the gaming giant in 2002 following on from allegations that Nintendo, and seven distributors had colluded to raise hardware and software prices between 1991 and 1998.
They were found guilty as charged and one of the biggest ever fines in EU competitions history levied against Nintendo.
But now the games console maker is fighting the fine.
"The penalty was unfair, illegal, even shocking", Ian Forrester, representing Nintendo, told the European Court of First Instance in Luxembourg.
He added: "This remains one of the biggest single fines in EU competition law".
But European authorities insist the fine was fair.
"The fine was not of a capricious nature, or based on wild estimates", said Xavier Lewis, a commission lawyer.
"This fine was for an infringement that was considered very serious."