Space tourists are a boost to Russia's contribution to the ISS

As he was carried away from the capsule, a grinning Mr Shuttleworth said: "Every second will be imprinted and will be with me for the rest of my life."

Mr Shuttleworth, a 28-year-old internet magnate, was rumoured to have paid $20m for his trip to the International Space Station (ISS).

He was joined on the descent from the ISS by the Russian crew commander Yuri Gidzenko and Italian flight engineer Roberto Vittori.

The Soyuz capsule successfully undocked from the ISS at 0031 GMT to begin a more than three-hour descent.

Mr Shuttleworth said the landing had been the most exciting part of his experience.

"It was more exciting than the launch because there we were closed off, we couldn't see out of the rocket. But on the landing we could see the flames and sparks, and the molten metal."

'Magical' ride

Mr Shuttleworth was greeted in Kazakhstan by his father, Rick, who said: "It was a wonderful feeling to see that parachute open."

The landing site was filled with helicopters and medical experts who carried out check-ups on the three crew members.

Italian Roberto Vittori was one of Shuttleworth's crewmates

After their medicals, the three men were flown to the Kazakh capital, Astana, for a welcoming ceremony. From there, they were to fly on to Russia's cosmonaut training centre at Star City in Moscow for further tests.

Mr Shuttleworth said his stay on board the ISS had been "magical" and that he would go up in space again if he had the chance.

He had spent some of his time carrying out scientific work on the ISS, including experiments on the virus responsible for Aids, and examinations of ocean life.

The South African is reported to have bought the Soyuz capsule and his space suit as a souvenir of his trip.

Mr Shuttleworth, who lives in London, is the world's second holidaymaker in space.

He follows in the footsteps of Dennis Tito, a US businessman and former American space agency (Nasa) employee, who rode into orbit last year.