Nadine Coyle has been accused of telling "porkie-pies" by former Girls Aloud bandmate Cheryl Fernandez-Versini over the decision behind the girl group splitting up.
When the band ended Nadine said she was against the idea - a claim Cheryl now disputes.
The X Factor judge told Attitude magazine the 29-year-old Londonderry woman was "full of s**t".
When Girls Aloud released an official announcement confirming they were splitting up in March 2013, LA-based Nadine stated her position.
"You should know I had no part in any of this split business," she wrote on Twitter. "I couldn't stop them. I had the best time & want to keep going. Xxxx."
But Cheryl has now disputed this. "She's full of s**t," the popstar told the gay lifestyle magazine. "What d'you want us to say? She's full of s**t.
"She was the one who wanted to make a solo record, which is why we took the hiatus.
"She wants to come out and say we broke the band up? No! She shouldn't tell porkie-pies.
"She should remember why we took the hiatus after seven years - so she could go and...
"Okay, so do you want us to tell the truth? She wasn't going to make another Girls Aloud record until she got a solo deal.
"I feel she held us to ransom and then made her solo record deal. It's the truth. She's saying that we broke the band up. So, there you go."
Nadine found fame with Cheryl, Nicola Roberts, Sarah Harding and Kimberley Walsh in 2002 on ITV's Popstar: The Rivals. Her solo material has not been the success she hoped for, but she garnered rave reviews for her performances last month as Goddess Erin in Michael Flatley's Lord Of The Dance: Dangerous Games.
So far, Nadine has failed to comment on Cheryl's claims about the end of Girls Aloud.