The world's richest eight individuals have as much wealth as 3.6bn people who make up the poorest half of the planet, according to research by Oxfam.
The charity said its figures show the gap between rich and poor was far greater than had been feared and has called for an overhaul of a "warped" economy that allowed a small group to have more wealth than they could ever spend while one in nine people went hungry.
Its report comes ahead of the World Economic Forum of global political and business leaders in Davos, Switzerland this week.
Mark Goldring, Oxfam GB chief executive, said: "It is beyond grotesque that a group of men who could easily fit in a single golf buggy own more than the poorest half of humanity.
"While one in nine people on the planet will go to bed hungry tonight a small handful of billionaires have so much wealth they would need several lifetimes to spend it.
"The fact that a super-rich elite are able to prosper at the expense of the rest of us at home and overseas shows how warped our economy has become."
Oxfam has said out-of-control pay ratios meant the average pay of FTSE100 chief executives was 129 times that of the average employee and works out to the equivalent of 10,000 people working in Bangladeshi garment factories.
It said new and better data on the distribution of global wealth, particularly in India and China, showed the poorest had less wealth than previously thought.
But the Adam Smith Institute free market think tank has accused Oxfam of putting out misleading information.
Head of research Ben Southwood said the welfare of world's poor was improving with the proportion of the global population surviving on less than $2 a day - falling from 69% in 1981 to 43% in 2008.
"Each year we are misled by Oxfam's wealth statistics," he said. "The data is fine - it comes from Credit Suisse - but the interpretation is not."
"It is not the wealth of the world's rich that matters, but the welfare of the world's poor - and this is improving every year.
"The consumption of the world's poor continues to rise, as does their education, healthcare, and height."
Who are the world's eight richest billionaires?
Among the eight billionaires from the latest research, are men who are known for their extensive philanthropic work.
Oxfam's report added: "The fortune of Bill Gates has risen 50% or 25 billion US dollars since he left Microsoft in 2006, despite his commendable efforts to give much of it away.
"If billionaires continue to secure these returns, we could see the world"s first trillionaire in 25 years.
"In such an environment, if you are already rich you have to try hard not to keep getting a lot richer."
Oxfam is now calling on international leaders to improve international cooperation to stop tax dodging, action to encourage companies to act for the benefit of staff as well as shareholders, wealth taxes to fund healthcare, education and job creation, and to improve opportunities for women.
It also urged business chiefs to commit to paying a living wage and their fair share of tax.