Coldplay have moved to deny claims from guitarist Joe Satriani that they used one of his riffs.
A copyright infringement suit filed by Satriani on Thursday claims Coldplay's Viva La Vida used "substantial original portions" of his 2004 instrumental track If I Could Fly.
But the Grammy nominees have now issued a statement declaring that the guitar legend "did not write or have any influence on the song".
Satriani's suit states the guitarist is seeking a jury trial, damages and "any and all profits" arising from the alleged plagiarism.
A number one hit for the band, Viva La Vida is credited to Coldplay's four members - Chris Martin, Guy Berryman, Johnny Buckland and Will Champion - and took its title from Mexican artist Frida Kahlo.
"With the greatest possible respect to Joe Satriani, we have now unfortunately found it necessary to respond publicly to his allegations," the band said on their website today.
"If there are any similarities between our two pieces of music, they are entirely coincidental and just as surprising to us as to him.
"Joe Satriani is a great musician but he did not write or have any influence on the song Viva La Vida."
The quartet have asked him to "accept our assurances" over the song.
Satriani's track was featured on his 2004 album Is There Love in Space?
The legal action represents the second time this year Coldplay have been accused of using another artist's melody.
Brooklyn-based indie group Creaky Boards claimed the tune of Viva La Vida is strikingly similar to that of their own track, ironically entitled The Songs I Didn't Write.
Coldplay were nominated for seven Grammy Awards earlier this week, with Viva La Vida up for the Record of the Year prize.