Darek Fidyka, who suffered his injury four years ago, can now walk with a frame and has been able to resume an independent life, even to the extent of driving a car.

Despite success in the laboratory, it is the first time the procedure has been shown to work in a human patient.

Researchers said the man was “not dancing but absolutely delighted” by the breakthrough.

Professor Geoffrey Raisman, whose team at University College London’s Institute of Neurology discovered the technique, said: “We believe that this procedure is the breakthrough which, as it is further developed, will result in a historic change in the currently hopeless outlook for people disabled by spinal cord injury.”

A Polish team led by one of the world’s top spinal repair experts, Dr Pawel Tabakow, from Wroclaw Medical University, performed the surgery.

The procedure involved transplanting olfactory ensheathing cells (OECs) from the nose to the spinal cord.

OECs assist the repair of damaged nerves that transmit smell messages by opening up pathways for them to the olfactory bulbs in the forebrain.

Re-located to the spinal cord, they appear to enable the ends of severed nerve fibres to grow and join together – something that was previously thought to be impossible.

While some patients with partial spinal injury have made remarkable recoveries, a complete break had generally been assumed to be unrepairable.

Prof Raisman said: “The observed wisdom is that the central nervous system cannot regenerate damaged connections. I’ve never believed that.

“Nerve fibres are trying to regenerate all the time. But there are two problems – crash barriers, which are scars, and a great big hole in the road. In order for the nerve fibres to express that ability they’ve always had to repair themselves, first the scar has to be opened up, and then you have to provide a channel that will lead them where they need to go.”

He stressed that what had been achieved was a leap forward beyond promoting “plasticity” – the re-wiring of remaining connections.

The research, funded by the Nicholls Spinal Injury Foundation (NSIF) and the UK Stem Cell Foundation, is featured in a special Panorama programme on BBC One tonight.

Prof Raisman compared plasticity with motorists finding other routes around a closed section of road.

“Imagine that part of the M1 motorway from London to Edinburgh has been washed away by the River Trent in the Midlands,” he said.

“Cars will eventually find their way through the B roads and country roads – that’s plasticity. Clearly it’s never going to be as efficient as using the motorway. What we’re doing is repairing the motorway, and it’s the first time this has been achieved.”

He said the procedure provided a bridge to enable cut nerve fibres to grow and meet.

Prof Raisman said his team was convinced that Darek’s recovery was due to the procedure, and not spontaneous repair through hidden residual nerve connections.

“The patient is now able to move around the hips and on the left side he’s experienced considerable recovery of the leg muscles,” said Prof Raisman.

“He can get around with a walker and he’s been able to resume much of his original life, including driving a car.

“He’s not dancing, but he’s absolutely delighted.”

David Nicholls, founder of NSIF, whose son Daniel was paralysed in a spinal injury accident in 2003, said: “Paralysis is something that most of us don’t know very much about, because we are not affected by it. One of the most devastating moments a parent will ever experience is the sight of their son or daughter lying motionless in bed and facing the reality that they may never walk again.”

He said the information would be made available to other researchers globally, in a bid to speed up the search for a condition which robs people of their lives.