By Ian Youngs
BBC News entertainment reporter
James Blunt is locked in a royalties dispute with a producer who says he helped write songs on the star's album.
James Blunt won two prizes at the recent Brit Awards
Royalty payments on six songs from Blunt's hit album Back to Bedlam have been frozen until the row is resolved.
Lukas Burton said he worked with Blunt at the start of his career but the star severed ties with him when other industry figures started taking notice.
Blunt's publicist said: "Traditionally, when a record is this massive, everyone wants to claim credit for its success."
She added: "This is no different." But she refused to give any further details.
Blunt's album sold two million copies in the UK in 2005 and he recently became the first UK artist to have a US number one single for nine years.
Mr Burton has written and produced for artists including Sir Paul McCartney, Dido and Amanda Ghost.
A spokesperson for the MCPS-PRS Alliance, which handles royalties in the UK, declined to name the songs involved in the dispute.
But she said Blunt's best-known single You're Beautiful was not among them.
"We've gone into standard dispute procedures and payment is frozen until we're advised otherwise," she said.
Writing on an internet site, Mr Burton said he met Blunt in 2001 and his music was "crude, occasionally laughably direct, and betrayed his relative lack of musicianship or discernible influence".
But Mr Burton could see the commercial potential and Blunt flew to Los Angeles so the pair could work together, he wrote. "A couple of people told me I shouldn't be working with him without a contract in place.
"But to be honest the love couldn't have been thicker in the air - lots of talk about how great the record was going to be and how cool the whole situation was."
But the relationship soured when Blunt was approached by a manager, Mr Burton wrote.
Blunt was told to "sever all ties" with the producer, according to Mr Burton.
"It wasn't so much that I was angry, just completely gutted," he wrote.
"I had pinned an awful lot of hope on the project and devoted a huge amount of painstaking effort to it.
"I had breathed life into it and I simply couldn't believe that the universe was going to repay me with such abject treachery.
"James is exactly as successful as I knew he would be, not that it does me, my bank balance or my family much good to say it."
Blunt's album is currently number two in the US and the star was named best pop act and best male solo artist at the Brit Awards.
Mr Burton's manager said the producer co-wrote three songs that appeared on Blunt's album.
He said the MCPS-PRS Alliance "considered that Lukas' claim has sufficient merit to suspend the distribution of royalties on those songs worldwide until such time as both parties have come to an agreement or the matter is settled in court".