V Festival organisers are hoping Cheryl Cole will still perform at the event - saying they have not been told that she is pulling out.
Their comments came as Cheryl - who has been diagnosed with the potentially deadly disease malaria - has been moved from a private clinic to receive specialist care.
The singer was transferred to University College London (UCL), which is home to the Hospital for Tropical Diseases, in the centre of the capital. A spokeswoman for UCL confirmed Cheryl was being treated at the Trust.
The star is said to have spent two hours in intensive care at an emergency unit of the Cromwell Hospital before being moved.
A spokesman for V Festival, where the star is set to perform, said: "V Festival has not been informed by Cheryl Cole's management that she will not be appearing at this year's festival. Unless otherwise informed, organisers are expecting her to appear as planned and wish her a speedy recovery."
Cheryl, 27, has pulled out of the last in the current series of X Factor auditions while she fights the disease.
An X Factor spokeswoman said: "We're not due to film with Cheryl again for a few weeks, so we will just keep in touch with her to see how things are going."
Cheryl contracted malaria on her trip to Tanzania last month despite taking malaria tablets. The singer and close friend Derek Hough spent six days together on Africa's east coast following her split from footballer Ashley.
Cheryl reportedly collapsed with suspected gastroenteritis during a photoshoot on Saturday, when she was initially diagnosed with exhaustion. But she was rushed to hospital the next day after her symptoms worsened.
V is on the weekend of August 21 at Hylands Park, Chelmsford and Weston Park, Staffordshire.
© Press Association