The nurse who transferred hoax callers to staff treating the Duchess of Cambridge has been found dead.
The King Edward VII Hospital announced the news of Jacintha Saldanha's death with "very deep sadness".
Hospital chief executive John Lofthouse said: "Our thoughts and deepest sympathies at this time are with her family and friends.
"Everyone is shocked by the loss of a much-loved and valued colleague."
Police were called at approximately 9.35am on Friday to reports of a woman found unconscious at an address in Weymouth Street, west London.
The death is being treated as unexplained.
John Lofthouse added: "We can confirm that Jacintha was recently the victim of a hoax call to the hospital. The hospital has been supporting her at this difficult time."
Two radio DJs from 2Day FM in Sydney impersonated the Queen and the Prince of Wales earlier this week, duping staff into giving a condition update on Kate, who was being treated for severe morning sickness.
The Duke and Duchess of Cambridge are "deeply saddened" by the news.
St James's Palace added: "Their Royal Highnesses were looked after so wonderfully well at all times by everybody at King Edward VII Hospital, and their thoughts and prayers are with Jacintha Saldanha's family, friends and colleagues at this very sad time."
In the wake of the tragedy the company which runs 2Day FM said that, by mutual consent, the hosts would not be returning to their show until further notice.
In a statement Southern Cross Austereo said: "Southern Cross Austereo (SCA) and 2Day FM are deeply saddened by the tragic news of the death of nurse Jacintha Saldanha from King Edward VII's Hospital and we extend our deepest sympathies to her family and all that have been affected by this situation around the world.
"Chief executive officer Rhys Holleran has spoken with the presenters. They are both deeply shocked and at this time we have agreed that they will not comment about the circumstances.
"SCA and the hosts have decided that they will not return to their radio show until further notice out of respect for what can only be described as a tragedy."