The US Patent and Trademark Office (USPTO) announced a patent owned by biotech company Aker BioMarine for krill oil production should be invalidated, giving another win to rival Norwegian krill oil maker Rimfrost.

Rimfrost has prevailed over Aker BioMarine in seven legal proceedings related to krill-oil patents.

"The uncertainty which Aker BioMarine sought to generate around our products and ability to deliver has once again been emphatically repudiated," said Rimfrost's principal shareholder Stig Remoy.

Earlier this year, Sore Sunnmore District Court invalidated Aker BioMarine's ownership of krill patents.

The company was forced to pay NOK 2.3 million (€235,823/$271,614) in court costs, following its claim to own the patents and have the right to use them and for seeking compensation from a previous dispute with Norwegian bank Nordea and government-backed Innovation Norway.

An appeal of that decision will be heard by Frostating Court of Appeal later this year.