Welsh opera singer Katherine Jenkins was mugged in south west London after she intervened in a "vicious" street robbery.
Her agent said the 39-year-old was on her way to a rehearsal at about 3.10pm on Wednesday when she witnessed an elderly woman being attacked.
After she stepped in to help, the singer was then mugged herself, her agent said.
The mezzo-soprano was in London to sing at the Henry van Straubenzee charity carol concert at St Luke's Church in Chelsea.
"Miraculously, Katherine still managed to perform at the concert as she didn't want to let the charity down," her agent added.
The Met Police said it was called to reports of a robbery on King's Road in Chelsea at about 3.10pm on December 4.
Officers attended the incident and arrested two 15-year-old girls on suspicion of robbery, a police spokesperson said.
"A female member of the public had attempted to intervene," the spokeswoman added.
Katherine was in London to sing at the Henry van Straubenzee memorial charity carol concert at St Luke's Church.
An officer was assaulted during the incident but did not require hospital treatment.
The two girls were released under investigation, but one was re-arrested on December 5 in connection with the same incident after further information was received.
She remains in custody.