Dr Dre and music mogul Jimmy Iovine have been ordered to pay $25.2m (£19.2m) to a former partner in their headphone company, Beats.
Steven Lamar claimed credit for the idea of creating a brand of celebrity-endorsed headphones.
He took the idea to Dre and Iovine in 2006; and the first Beats headphones were released two years later, based on a design by Robert Brunner.
The parties later fell out, and Lamar sued over unpaid royalties in 2016.
At the centre of their dispute was a 2007 settlement, in which Dre and Iovine agreed to pay Lamar 4% of the base price of every headphone they sold.
Only one model, Beats Studio, was specified but Lamar argued the design had been carried over to a dozen different models, and sought $130m (£99m) in royalties.
A jury in Los Angeles decided that three pairs of headphones – the Studio 2 Remastered, the Studio 2 Wireless and the Studio 3 – had design similarities; and ordered that Dre and Iovine should pay Lamar $25,247,350.
With the Studio 3 still on sale, the verdict means Lamar will continue to receive royalties in addition to the court-mandated payout.
The trial saw Dre and Iovine testify about the origin of Beats – a story they told at length in the recent HBO documentary series The Defiant Ones.
Lamar’s lawyer said the jury had seen through their attempts to gloss over his client’s role.
“They tried to paint him as some guy who was just there at the right time and the right place, and they already had the idea,” Brian Melton told Billboard.
“I don’t think that was it at all and I think we proved just the opposite: That before they met Lamar, they hadn’t thought about this and he gave it to them on a silver platter.
He added: “For anybody who has a great idea and brings it to a company and then doesn’t get the recognition or credit that they’re due… what this jury verdict says is, if that happens to you and you’re a little person, you can go into court and have a jury of American citizens determine whether you’re right or wrong.
“And if you’re right, you get the credit that you’re owed.”
Beats, which later became a music streaming service as well as a headphone company, was acquired by Apple Music in a $3bn deal in 2014.
Lamar’s legal case was filed before that deal, and did not name Apple as a defendant.