The singer was a member of the popular girlband alongside Cheryl, Nadine Coyle, Kimberley Walsh and Nicola Roberts.
The reports began after new mum Cheryl and Sarah seemingly unfollowed each other on social media.
During her first week in the CBB house, Sarah refused to confirm a fight had occurred between her and Cheryl.
And now, Sarah has got candid about who she still speaks to in the band.
In scenes set to air on Saturday night, Sarah reveals Nadine is the only Girls Aloud star she’s still close with.
Speaking to fellow housemates Paul Danan and Amelia Lily, Sarah confesses that she doesn’t speak to the other girls.
“I haven’t seen any of them for a long time,” she admits to her co-stars, before revealing she spoke to Nadine “a couple of weeks ago on FaceTime”.”
“Nadine and I have stayed more in touch because we were always the ones that were more independent you know,” she explains.
Sarah also confesses that the fact Nadine has made her home in the US has made it hard for them to maintain a relationship.
“She’s in LA all the time so I don’t really speak to any of them at the moment, so it’s hard,” says Sarah.
“We’ve got our own lives going on. We’ve got our own things.”
Nadine was the only member of Girls Aloud to wish Sarah good luck on social media after she entered the house earlier this month.
Celebrity Big Brother continues weeknights at 9pm on Channel 5.