Louise Redknapp, 44, who got divorced from Jamie Redknapp, 45, two years ago, reached the Strictly Come Dancing final in 2016 with Kevin Clifton, 36.
The two appeared to have a great friendship, having supported each other at various events since appearing on the BBC One show.
But, it’s now been reported Louise has been “dropped like a stone” by the Grimsby-born dancer since he got together with his celebrity partner from last year, Stacey Dooley.
A source told The Sun: “Louise is seething — she feels used and humiliated by Kevin. They formed an incredibly close bond during Strictly, which grew and grew once the show finished.
“They enjoyed several nights out together, and Kevin became her closest confidant once her marriage to Jamie ended.”
They added Louise and Kevin were in “constant contact” and remained close since they were on the dancing competition.
The source continued: “But as soon as he got paired with Stacey last year, he stopped returning her calls and effectively ghosted her.
“She even went up to Grimsby in December to support Kevin at a charity fundraiser, but relations soured pretty much from here onward. Louise feels hurt and let down by his actions — she was the famous one and helped bolster his profile.
“Now she feels a bit of a mug after being dropped like a stone as soon as someone else came along.
Louise is reportedly considering complaining to BBC bosses to “air her feelings”.
The singer recently admitted she hasn’t been in contact with Kevin this year and they are believed to have unfollowed each other on social media.
Louise, who is currently starring in 9 To 5: The Musical at London’s Savoy Theatre, told The Sun: “I haven’t spoken to him for a long time.
“Most probably since the show started. Not since last year.”
Kevin is now reportedly dating his Strictly Come Dancing partner, Stacey, but Louise has chosen not to “pass judgment”.
“I haven’t spoken to Kevin in a long, long time and I’ve never met Stacey, so I have no idea,” she said.
“Everyone has a different experience, everybody does the show for different reasons, everyone is looking for something different.”
Kevin and Stacey are rumoured to be dating after the documentary maker split from her boyfriend of five years, Sam Tucknott.
They appeared to confirm their relationship by sharing matching snaps together on Instagram this week following Kevin’s performance in show, Burn The Floor.
In the picture, Kevin can be seen with his arm draped around Stacey’s shoulder as she reached up to hold his hand.
Express.co.uk has contacted Louise Redknapp and Kevin Clifton’s representatives for comment.