CANBERRA, Australia (AP) — Australia's highest court has rejected British company Reckitt Benckiser's appeal of a 6 million Australian dollar ($4.5 million) fine for misleading consumers about the effectiveness of a popular painkiller.

The High Court refused to hear the appeal after Reckitt Benckiser's lawyers outlined its argument on Wednesday for why the fine imposed by the Federal Court in December was too high.

The Federal Court had upheld an appeal by the Australian Competition and Consumer Commission, the watchdog that launched the court action, against the leniency of a AU$1.7 million fine.

Reckitt Benckiser sold Nurofen painkillers that were marketed to relieve specific ailments, such as back pain and menstrual pain, when all of the products contained an identical amount of the same active ingredient, ibuprofen lysine.