A driver who knocked down and killed a woman in Bristol suffered a massive low blood sugar attack at the time and could not be blamed, a court heard.

Bristol Crown Court was told James Higgs suffered the hypoglycaemic episode as he drove his Vauxhall Astra on Bath Road on a Sunday evening in January 2007.

He hit pedestrian Pamela Beckett, 37, who worked in the library at BBC Bristol, Whiteladies Road, causing fatal multiple injuries.

Mr Higgs, 32, of Barrs Court, Longwell Green, was due to stand trial after being charged with causing death by dangerous driving.

But yesterday, after a review of expert evidence in the case, the Crown Prosecution Service offered no evidence and Judge Jamie Tabor QC asked for a not guilty verdict to be recorded.

The judge, who heard Mr Higgs had never been advised to pre-test for his condition before driving, told the court: "The onset of such an attack comes out of the blue, without warning, and if that is the case isn't it so that some form of pre-testing is required?

"This is a very, very tragic case. The only mitigation has been the dignity which the deceased's family, and the defendant's family, have borne. I applaud it."

Mr Higgs, who expressed his regret for the tragedy through his barrister, declined to comment further.

Family and friends of Ms Beckett, from Birmingham, who attended court and were consulted by the CPS, also said they wished to make no comment.

Simon Morgan, prosecuting, told the court the central issue in the case was if Mr Higgs drove knowing he might have an attack or when he was in the throes of one.

Mr Morgan said Mr Higgs had made references to hypoglycaemia both to a paramedic at the scene and a triage nurse in hospital, but those references were deemed "unreliable" due to the attack.

He said: "The nurse said she had never come across a person with such a low blood sugar level.

"In this case it is accepted by the crown's expert that it would not be possible to say he (Mr Higgs) would be aware he was suffering a hypoglycaemic attack."

Mr Morgan said he therefore offered no evidence, telling the judge: "I have discussed it with the family of Pamela Beckett, whose dignity I would be proud of. They understand, and they have expressed some sympathy for the defendant. It is a complete tragedy, worsened by the delay in bringing these proceedings to a conclusion."

Ian Bridge, defending, said his client had been diagnosed with Type 1 diabetes since the age of 12 and he had never been advised to pre-test for his condition before driving.

"He wishes me to offer his sincere regret and apology in so far as he is to blame. He is very, very concerned and upset about what happened, as are his family.

"He hopes everybody accepts that the upshot of today is that he was not aware and not deliberately taking a risk, and would not do so."

Mr Bridge added that his client had never before suffered such a severe attack. He said: "There are hundreds of thousands of people who have this condition and almost all manage the condition well, are able to drive and hold down very responsible jobs including surgeons and judges."

Diabetes.co.uk, the online support group for diabetics, recommends that people with the condition should not drive if they have difficulty recognising the early signs of hypoglycaemia, and they should check their blood sugar levels before and during driving.