Joss Stone has pulled out of a scheduled gig in a pub, claiming she had been "compromised" by the event.
The star was due to appear alongside Yes Sir Boss in her home county of Devon tomorrow evening, at an invites-only show.
However, after finding out tickets for the concert were being sold off the back of her appearance, she had decided not to play with the group, who have previously supported her.
A spokesman for Stone said she was unhappy that money was changing hands for the event at the 150-capacity Drakes pub in Topsham.
He explained: "Joss feels completely compromised and never agreed to that approach.
Meanwhile, reggae act Yes Sir Boss have vowed to go ahead with the show, admitting they are "devastated" at the news.
Manager Elwynne Green said: "It has cost us a lot of money and would have been a major show for the band.
"We are absolutely devastated that Joss isn't appearing, but we are still going to put on an amazing show for our fans."