Channel 5 is seeking a part-refund from the company that made Don't Stop Believing, according to Broadcast.
The network's new owner Northern & Shell is apparently "unhappy" with the performance of the Glee-inspired reality series, which aimed to find the UK's best amateur singing ensemble.
The magazine reports that C5 is trying to recoup some of the estimated £6 million it paid Shine TV for the series. However, the broadcaster is thought to be already overdue on outstanding payments to the indie.
Ratings for Believing, which aired over six weeks in the summer, dropped as low as 587,000 in its primetime Sunday slot.
