Ed Sheeran has signed a secret deal to settle a $20 million lawsuit over his hit ballad “Photograph,” which it has been alleged was copied “note-for-note” from an obscure, low-charting song by a British talent show winner.

Songwriters Thomas Leonard and Martin Harrington—who were represented by Richard Busch, the same lawyer who won a $7.4 million copyright-infringement case in 2015 against Robin Thicke and Pharrell Williams over their single “Blurred Lines”—accused Sheeran of “unabashedly taking credit” for their work, saying he had engaged in “note-for-note” copying of a track called “Amazing,” which was released by Matt Cardle, the winner of the U.K. talent show X Factor in 2012.

The songwriters said in court documents that the chorus of the two songs shared 39 identical notes, with similarities “instantly recognizable to the ordinary observer.”

Their suit accused Sheeran and his songwriting partner ,Johnny McDaid from the band Snow Patrol, of copying, saying they had “exploited, without authorization or credit, the work of other active, professional songwriters on a breathtaking scale.”

They submitted the chord structures for both tracks in court documents, and stated: “While Sheeran, McDaid, and the other defendants received career-defining accolades, awards, and a fortune for ‘Photograph,’ the true writers of much of ‘Photograph’ received nothing.”

An order signed by judge James Selna at a California court on Monday said the case had been dismissed after an agreement had been reached between the parties, but details of the settlement were not revealed in the court papers.

Sheeran’s single “Photograph,” from his album x (Multiply), reached No. 10 on the U.S. Billboard Hot 100 and No. 15 in the U.K. singles chart in 2014.

Cardle’s track “Amazing” peaked at No. 84 in the U.K. in 2012.