Space age: Jeff Bezos, with wife MacKenzie, is investing in slowing the ageing process

Amazon founder Jeff Bezos, whose hobby is launching rockets into space, is the world's richest man with a £90billion fortune, a Gulfstream jet and a string of mansions dotted across America.

Who could blame him for wanting to live for ever?

The 54-year-old internet tycoon and a handful of Silicon Valley billionaires are investing chunks of their vast wealth in efforts to extend life by slowing the ageing process.

They include PayPal co-founder Peter Thiel, Oracle founder Larry Ellison and Google billionaires Larry Page and Sergey Brin.

The excitement about longevity is on a par with the buzz surrounding the internet in 1995, according to Jim Mellon, one of Britain's most successful investors who is leading the anti-ageing race on this side of the Atlantic.

Mellon, who has been dubbed Britain's Warren Buffett, has set up his own company, Juvenescence, to invest in drugs to extend life – also known as biogerontology.

Last year, he was appointed to the Biogerontology Research Foundation's board of trustees.

He predicts that medical breakthroughs in age-related diseases such as cancer, new drugs and healthier lifestyles will drive the average life expectancy up to between 110 and 120 years over the next three decades.

In 20 years' time, the race to extend life will be the biggest business in the world and 'much more important than the trivial uses of the internet like Facebook and Snapchat', he said.

The 61-year-old's biggest financial success to date was setting up uranium miner UraMin with $100,000 capital in 2005.

He sold it two years later to French nuclear power giant Areva for around £1.6billion.

Google has been quietly spending big on anti-ageing drugs through a project called Calico. When it was founded in 2013, Larry Page said it would focus on 'health, well-being, and longevity'

Jim Mellon, one of Britain's most successful investors, is leading the anti-ageing race on this side of the Atlantic

He has also invested heavily in property in Germany and the Isle of Man, where he is based, but has more recently turned his attentions to biotech.

His influence is wide. He reputedly introduced Nigel Farage to Arron Banks, who subsequently became Ukip's biggest donor.

But he sees problems down the road with rising longevity. He claims politicians around the world are not doing enough to plan for the consequences, such as rising pressure on pensions.

Mellon, whose wealth is estimated at £920million, suggests the coming changes will see people working way past the current retirement age.

'The trajectory of life is going to change and no governments are taking account of this,' said Mellon, who yesterday gave a talk on the subject at his Master Investor show in London.

'So many aspects of our lives are going to be up-ended, most importantly pension funds. There will be no one – companies or governments – who will be able to support a retirement age of 65 if people are going to live that long.'

Amazon founder Jeff Bezos, whose hobby is launching rockets into space, is also investing chunks of his vast wealth in efforts to extend life by slowing the ageing process

He compares 20th Century Britons who worked most of their lives with subsequent generations that could be 'only working for about a third of their life'.

He warns: 'No one can support that. Someone's got to promulgate this because otherwise there's going to be an economic disaster.'

But he said investment opportunities are about to go mainstream.

'As soon as Silicon Valley and rich people in America start getting involved in this, you'll get companies going public,' he said, referring to firms selling shares on the stock market.

It is still early days for Juvenescence. It hopes to carry out human trials 'in the next two or three years' and has plans for a stock market float.

'It's not in a state to go public yet but it will be by the end of this year,' he said.

In the US, Unity Biotechnology, the company that Bezos has backed through his firm Bezos Expeditions, has a $150million (£107million) war chest to develop drugs that 'prevent, halt, or reverse numerous diseases of ageing'.

Unity also counts Thiel, who is a life-extension enthusiast, as an investor. It has further, more traditional, investment from asset management giants Fidelity and Edinburgh-based Baillie Gifford.

Google has also been quietly spending big on anti-ageing drugs through a project called Calico.

When it was founded in 2013, Larry Page said it would focus on 'health, well-being, and longevity'.

Along with its partner AbbVie, the pharmaceutical giant, it plans to invest up to $1.5billion to find cures for diseases like cancer and Alzheimer's, but it has so far kept quiet on its progress.

Closer to home, Mellon is hoping Juvenescence can play a role in prolonging life.

'If we can be a small part of something enormous, that's pretty exciting,' he said.