LONDON, August 6, 2008 (AFP) - Buckingham Palace denied a report on Wednesday that Queen Elizabeth II's elderly husband Prince Philip has been diagnosed with prostate cancer.

In a statement, the palace said: 'The Duke of Edinburgh has authorised us to confirm that the claim made by the Evening Standard that he has received a 'diagnosis of prostate cancer' is untrue.'

The London newspaper reported earlier that the 87-year-old was diagnosed with cancer while being treated in a hospital in the capital for a chest infection in April.

The palace said it believed the front-page story was 'a serious breach of Prince Philip's privacy'.

'Buckingham Palace has always maintained that members of the Royal Family have a right to privacy, particularly in relation to their personal health,' it said.

'For this reason, we have always refused to confirm or deny the persistent rumours that circulate about their health, particularly during the quieter news months.'

But it said it had taken the unusual step of formally denying the rumours 'because the damaging story is now being reported widely'.

The Evening Standard quoted an unnamed cancer specialist as saying: 'It's become an open secret within the medical community that Philip has prostate cancer.

'If he'd had a serious chest infection that was so worrying it required hospitalisation, he wouldn't have walked in and out of there smiling and been 'sitting up in bed replying to letters'.'

On Wednesday the prince was in Cowes on the Isle of Wight for the annual sailing week, a royal spokeswoman said.