The Prince of Wales and the Duchess of Cornwall were left laughing uncontrollably by a musical performance during a visit to an eco-festival in London.

Performer Henry Dagg first gave a rendition of A Nightingale Sang in Berkeley Square playing a saw with a bow, which amused other famous faces including Jools Holland and Brian Blessed.

But it was the introduction of his "cat organ" consisting of a row of squeaking toys that really evoked the laughter from Prince Charles and Camilla.