The Duchess of Cornwall has been forced to cancel her appearance at a military event in Hampshire due to a bout of gastroenteritis, Clarence House has said.

Camilla, who is commodore-in-chief of the Royal Naval Medical Services, was due to present medals and take the salute of personnel to mark the completion of Operation Gritrock, the UK's contribution to the anti-Ebola effort.

A Clarence House spokesman said that after becoming ill and seeking medical advice from a doctor she took the decision not to travel to the event.

He added: ''The Duchess of Cornwall has been forced to withdraw from an engagement in Portsmouth this morning due to a bout of gastroenteritis.

''Her Royal Highness is very disappointed that she will be unable to present medals and take the salute to mark the completion of Operation Gritrock, the UK's support to the global Ebola threat.

''The First Sea Lord, Admiral Sir George Zambellas, who was due to present medals alongside the Duchess, will continue the event and read the Duchess's speech.''