Carrie Underwood and Kelly Clarkson might be the top 'American Idol' earners of all time, but it turns out the two are among a handful of contestants that might be owed even more money.

According to Fox News, a federal lawsuit has been filed in New York City claiming that Sony Music Entertainment cheated several contestants, including Underwood and Clarkson, out of at least $10 million in royalties.

The lawsuit was filed on Thursday (Feb. 20) by 'Idol' creator Simon Fuller's company, 19 Recordings, which has exclusive rights to the contestants on the hit TV show. The legal filing alleges that two separate audits of Sony's records confirm their findings.

Other artists mentioned in the lawsuit include Clay Aiken, Jordin Sparks and Chris Daughtry. Sony Music declined to comment on the case.

Underwood reclaimed her top spot as the No. 1 'American Idol' earner last year, making an impressive $31 million from June 2012 to June 2013. That number is $24 million more than Clarkson's income, who came in second with $7 million.

The 'See You Again' singer also claims the highest spot on The Boot's list of the Top 10 'American Idol' singers, thanks in part to her 12 No. 1 hits and four multi-platinum albums.

Fellow country star Keith Urban joins Jennifer Lopez and Harry Connick, Jr. in judging Season 13 of 'American Idol,' which airs on Wednesday and Thursday nights at 8PM ET on Fox.