Sugababe is reportedly being threatened with the sack only 18 months after joining the band.

The singer has apparently �gone underground� over pressure from all sides to dump her boyfriend Freddie Fuller, who is currently awaiting trial for the alleged rape of her 20-year-old sister Samiya.

A source tells the Sunday Mirror, �The other two girls, the management and the label have threatened to axe her unless she dumps him.

"She's gone underground and has refused to answer their calls - but it will all climax this week.

"Amelle has got a serious decision to make."

However, a spokesperson for the Sugababes says, "As far as we're concerned, it's business as usual."