Stephen Hawking may have been misdiagnosed and actually a victim of polio, a US medical expert has suggested.

Christopher B Cooper, Professor Emeritus of Medicine and Physiology at the University of California, Los Angeles, said the probability the physicist’s famously debilitating condition was in fact amyotrophic lateral sclerosis (ALS) was “low”.

He said Hawking’s relatively young age of diagnosis, 21, and his 55-year period of survival does “not match our understanding of ALS”.

In a letter to the Financial Times, the medic argued it is more likely Hawking’s neurological and motor system impairment was caused by poliomylitis, of which there was epidemics in both America and Europe in 1916 and 1952.

“Perhaps Hawking was unlucky to contract poliomyelitis or a similar viral infection a few years later in 1963,” he said.

The pioneering theoretical physicist, who died last Wednesday aged 76, was equally famous for being completely dependent on a wheelchair for movement and a computerised voice system for communication for his theories on the origins of the universe.

His long illness confounded doctors, who gave him just two years to live upon being diagnosed in 1963.

“Typically, its [ALS’s] onset is in the later years of life,” wrote Professor Cooper.

“Usually, it is relentlessly progressive and the median survival from the time of diagnosis is around three years with fewer than 20 per cent of ALS patients surviving longer than 10 years.”

Polio is a serious viral infection which was common in the UK until routine vaccination was introduced in the mid-1950s.

Last week it was revealed Hawking completed a final theory before he died which laid the mathematical groundwork for the detection of multiple universes, or a “multiverse”.

The existence of multiple big bangs was a troubling implication of his 1983 “no-boundary” theory.

Last week colleagues suggested new paper could enable a spaceship to detect radiation traces from multiple big bangs.

Telegraph UK