Browser maker Opera has filed a lawsuit against a former employee, alleging he shared trade secrets with rival Mozilla. Designer and musician Trond Werner Hansen is on the hook for 20 million Norwegian Krone, or about $3.4 million in damages according to a report from TNW.

Hansen worked with Mozilla as recently as last year when he helped design and develop a prototype browser for the iPad under the codename Junior. As evidence, Opera highlighted a video of Hansen speaking about the project with Firefox product design lead Alex Limi. It’s not so much what Hansen discusses in the video that got them upset but rather what Limi was showing – innovations that Opera was or still is working on.

Opera’s lawyer, Bing Hodneland Advokatselskap partner Ole E. Tokvam, said in a note to TNW that the dispute is pending before the courts and as such, they choose not to comment on the case in detail. That said, they did confirm that Hansen was a former employee and consultant at Opera and that they are of the opinion that Hansen acted contrary to his contractual and other legal obligations towards Opera, the duty of loyalty and his confidentiality obligations.

Hansen was employed by Opera from 1999 through 2000 and again as a consultant from 2009 to 2010. He is reportedly responsible for a number of early browser innovations that first came to light in Opera software such as speed dial, tabbed browsing, integrated search and mouse gestures.