Is the world's most famous scientist victim of assaults? Hawking denies it, but police open an investigation

His fame as one of the most formidable intellects ever to theorise the universe has earned him worldwide adulation, millions of pounds and cameo appearances in Star Trek and The Simpsons.

But the ability of Professor Stephen Hawking to astound and confound those around him had its origins yesterday in a far less ethereal source - an investigation by Cambridgeshire Police into claims that he has fallen victim to a series of assaults which the acclaimed genius chooses not to explain.

The 62-year-old academic, whose discourses on the origins of time and matter have made him a fortune of £10m, was last night continuing a long recovery from a bout of pneumonia at Addenbrooke's Hospital in Cambridge, where he is visited daily by his second wife and former nurse, Elaine.

The illness, a consequence of the motor neurone disease which confines him to a wheelchair by paralysing and wasting his body, is separate from the issue being investigated by a senior detective - injuries suffered by Professor Hawking in recent months ranging from sunstroke to a broken wrist.

Cambridgeshire Police confirmed yesterday that they were waiting to interview a former nurse to the physicist, who requires constant professional care, after she claimed to have been a witness to some of the injuries.

The nurse, who is abroad, told the Daily Mirror newspaper that she had seen him with a three-inch cut to his throat after he had been shaved and that he had suffered heatstroke and sunburn on the hottest day of the year last summer when he was left stranded in the garden of his large chalet-style home in Cambridge.

A spokesman for Cambridgeshire Police, which has been investigating the claims since late last year, said: "We are investigating allegations of assault against a 62-year-old man from Cambridge. We have been approached with this fresh information and hope to interview the person concerned shortly."

Friends say the professor, the father of three grown-up children, has been a regular visitor to the accident and emergency department at Addenbrooke's with injuries such as cuts and bruising to the face, a broken arm and a wrist broken against his wheelchair.

Those close to Cambridge University's Lucasian Professor of Mathematics, a post once held by Sir Isaac Newton, say they are distraught at his refusal to discuss his injuries.

His first wife, Jane, told The Independent yesterday that she and her three children with Professor Hawking were unable to tolerate the alleged assaults or the self-imposed veil of silence of the apparent victim.

The nurse interviewed by the Daily Mirror said the academic had suffered a number of mysterious injuries while she was working for him, including a fractured femur, a cut lip and gashes to the face.

Speaking from her home in the university town, Jane said: "Today's newspaper revelations have made me feel ill to see the nature of injuries that Stephen has suffered.

"I am extremely worried about him. He is a special man and a vulnerable man but when his children see the aftermath of these events, they can only tell him that he must do something about it."

Tim Hawking, 24, the professor's youngest son, said his father always denied that his injuries were the result of an attack: "I'm very concerned. He denies it every time I speak to him about it and I would hope he would me respect me enough to tell me the truth."

At the home of the academic, who until recently could be seen frequently in the streets around the ancient colleges in Cambridge and is a regular visitor to the town's arts cinema, the curtains were drawn in daylight hours. In one alcove was a framed wedding picture while two bicycles stood unlocked in the garden.

One close friend said that Professor Hawking, who was given months to live when his illness was discovered at the age of 20 and is Britain's longest surviving motor neurone disease sufferer, was exhibiting a characteristic obstinacy.

The friend said: "He is a proud and stubborn man. It is the same obstinacy that has kept him alive. But on these injuries, he has steadfastly refused to do anything about it and we just don't dare think about what could come next. When you visit him in hospital he just types out on his screen that it isn't a good time to talk about it."

Undaunted by his condition, the professor has lived life at a hectic pace. As well as his best seller, A Brief History of Time, his 1988 explanation of his theory of quantum physics which has sold 25 million copies, he has written extensively to bring his science to a popular audience.

Speaking through an electronic voice box which has given him his synthesised voice, he has been invited to the White House by former US President Bill Clinton, feted by Hollywood stars and regularly lectures abroad.

But his private life has been fraught. In 1990, he left Jane after declaring that he had given his love to Elaine Mason, who had been one of his nurses since 1985. The couple married nine years ago.

Elaine Hawking, 53, who yesterday remained at their home surrounded by 6ft wooden fences and dense shrubbery, declined to discuss the police investigation when approached by The Independent.

In a statement earlier this week, her husband said: "There is absolutely no substance to the reports." But police said their investigation would continue and that they needed to talk to Professor Hawking once he is feeling well enough. A spokeswoman said: "We would make it clear that we would still like to speak to the professor to clear this matter up once and for all."