William was praised for mucking in on his last trip

William, 18, is due to begin his studies at St Andrews University in Scotland later this year.

The Prince has already spent 10 weeks in Chile on a Raleigh International expedition as part of his gap year.

On his visit to remote Patagonia he was pictured carrying heavy posts, teaching English to local children and even cleaning a toilet.

William decided to join the expedition during his gap year between school and university because he wanted to do something "different" and help people.

But unlike his visit to Chile, the Africa trip has been independently arranged and is not linked to any organisation.

Farm hand

Before leaving for Africa, Prince William gained some work experience as a farm hand on a dairy farm in the south west of England.

He worked at the farm from mid-January to mid-February and took part in a variety of farm jobs, but was not affected by the current farming crisis.

A St James' Palace spokeswoman said: "Prince William was unaffected by the outbreak of foot-and-mouth. He had completed his work on the farm some time before the outbreak."

She refused to name the farm where the Prince spent his work experience.

She added: "The Prince of Wales and Prince William continue to be grateful to all the media for respecting Prince William's privacy."