Kimberley Walsh has hinted that Nadine Coyle's distance from Girls Aloud may have caused the group's split.
The 31-year-old singer, who is closest to bandmates Cheryl Cole and Nicola Roberts, admitted that Nadine's move to Los Angeles caused a bigger "wedge" between the band in her autobiography A Whole Lot Of History, which is serialised in The Sun.
"Originally Nadine and I had been very close but by early 2007, we had drifted apart. In the end I felt like there was no common ground between us," she said.
Nadine's decision to get her own manager away from Girls Aloud didn't help things.
Kimberley continued: "The following Out Of Control tour in the spring of 2009 wasn't the beginning of the end for Girls Aloud - it was almost the end of the end. There had been a weird atmosphere within the band ever since we found out about Nadine's manager.
"We felt like we'd been sucker-punched. We'd known for some time her loyalty didn't really lie with us as a group any more, and we knew we couldn't force her to stay. For a long time, the rest of us felt she was holding us to ransom..."
Kimberley admitted the group were "surprised" when Nadine said she wanted Girls Aloud to continue after they announced their split on Twitter in March, after the Ten: The Hits Tour.
"It was quite a hard piece of news to swallow because she never said any such thing to the rest of us," she said.
Kimberley also revealed that Louis Walsh was "scared" of managing the girl group.
"He has since admitted to me he didn't know what to do with five girls and that he was a bit scared of us... His disappearing act meant we had nobody looking after us."