As heir to the throne, he has spent his entire life under the watchful eye of protection officers.

Rarely, though, would the Prince of Wales have enjoyed quite such specialised security as he did today: from a veteran "monkey guard".

The Prince, who visited a spectacular treetop walkway over a rainforest in Singapore, was kept safe from marauding primates by a monkey minder wielding a long stick to keep the most mischievous at bay.

The careful attention of the ranger, who works to keep long-tailed macaques away from the visitors' bags they like to search for food, ensure the Prince enjoyed an uninterrupted walk across an 80-foot-high metal walkway above the forest.

The Prince, who declared the experience "marvellous", later said he hoped the work of the rangers would convince the public to care about the environment before it was too late to save it.

The visit to the MacRitchie Reservoir Park saw the Prince speak of his fears that the wide public were not appreciating the world's natural resources "before it's all gone, before it's too late".