A mobile-phone billionaire will join an Everest experimental medical team after donating £½m to the project.

Former Phones4U boss John Caudwell will be part of the team climbing the world’s highest peak to study the effects of low oxygen levels on the human body.

As reported on grough in August last year, the Xtreme-Everest expedition will consist of 40 doctors and 200 volunteers climbing the Himalayan mountain in March. He, his brother Brian and four of their friends were among the first to volunteer when the project was launched.

The Staffordshire businessman is a confirmed action man, who has taken part in 1,000-mile bike rides and has even been known to cycle from his Stoke base to London. His personal fortune after selling the mobile phone business is estimated around £1.6 billion. He has also raised £8m for the Caudwell Charity, which helps children with medical conditions.

Expedition leader Dr Mike Grocott said: "We hope it will increase our understanding of what is making critically-ill people ill and give us the opportunity to develop treatments to help.

"The research is very significant and could help people in intensive care around the world."