Prince Harry has secretly attended a lavish 'top secret' summer camp run by internet search giant Google at one of the most exclusive resorts in Italy

Prince Harry has secretly attended a lavish 'top secret' summer camp run by internet search giant Google at one of the most exclusive resorts in Italy.

His presence at the event this week was not listed on the Court Circular, the official record of royal engagements, but saw him enjoy the opulence of the luxury retreat for the rich and famous, while rubbing shoulders with the likes of Elton John and Emma Watson, as well as Indian billionaire Lakshmi Mittal.

The annual event is held at the £1,500-a-night Verdura Resort, an opulent Rocco Forte Hotel, set in a valley of olive groves close to Sciacca on the island of Sicily, by Google billionaire co-founders Larry Page and Sergey Brin.

Each year they invite some of the world's wealthiest business leaders and tech gurus, as well as a handful of superstars, to spend three days discussing everything from human rights to the internet.

But while the mornings are dedicated to serious discussion, guests can spend their afternoons and evenings indulging themselves with lavish lunches, dinners and entertainment.

There are days trips around the coast, visit to wineries and local tourist spots, as well as spa treatments

On the last evening of the camp, Google spends an estimated £70,000 renting the massive 2,500-year-old Valley of the Temples ruins for a spectacular concert and sit-down dinner for 300 people.

This year the star turns were singers Elton John and Lenny Kravtiz.

The event is held amid huge secrecy.

The annual event is held at the £1,500-a-night Verdura Resort, an opulent Rocco Forte Hotel, set in a valley of olive groves close to Sciacca on the island of Sicily

Guests are given a password protected webpage on which the itinerary for their jaunt has been shared and instructed not to publicise it on social media.

Some have dubbed the three-day conference as 'Davos on the sea', after the World Economic Forum meeting held in the upmarket ski resort each winter often attended by Harry's uncle, Prince Andrew.

It is not clear why the prince was invited on the multi-million pound jolly, although he and his brother, Prince William, have declared an interest in exploring how the internet can be both used and policed when it comes to mental health and bullying issues, a key component of their public work.

Kensington Palace refused to discuss whether the Queen's grandson, who is fifth in line to the throne, was attending in an official capacity on behalf of the royal family, saying that they would not discuss 'private travel plans'.