A surgeon accused of killing a patient after he was given an overdose of anaesthetic has been cleared of manslaughter.

Andrew Ryan died after he was injected with four times the prescribed level of drugs during a routine operation at Shotley Bridge Hospital, near Consett, County Durham, on July 25, 1997.

The 20-year-old, who weighed about three-and-a-half stone, suffered from muscular dystrophy.

Newcastle Crown Court was told that Pravin Patel, from Harrow, Middlesex, admitted injecting Mr Ryan with ten millilitres of two per cent lignocaine - the anaesthetic - equating to a 200mg dose.

The jury heard that 200mg was the maximum dose for a healthy adult and that Mr Ryan should have been given a maximum dose of 60mg.

Jeremy Hill-Baker, prosecuting, said that Mr Patel was guilty of gross negligence, and therefore manslaughter, after not ascertaining Mr Ryan's weight to calculate the amount of drug he should be given, and instead had "taken a guess".

But after two hours deliberation, the jury of seven women and five men found him not guilty.

Mr Patel admitted he was negligent in giving Mr Ryan too much of the drug but had denied that his actions were grossly negligent.

The jury had been told that Mr Ryan's illness meant he was on the "cusp of life" at the time of the operation and could have died due to the trauma of the operation, even with a smaller dose.

Mr Patel, of Harrow, Middlesex, refused to comment after the hearing, but his solicitor, Ian Barker, said: "Mr Patel first and foremost wishes to extend his very sincere sympathies to Mrs Ryan and her family for their tragic loss.

"He is pleased that the jury clearly gave necessary careful consideration and that they have judged him not to be guilty of a crime.

"This case has been a considerable strain on Mr Patel and he will now be spending time with his family."

Mrs Ryan, who had sat throughout the entire case but left as soon as the jury delivered its verdict, did not wish to comment.

Detective Sergeant Ken Donnelly said: "She is clearly disappointed. It has been a long, hard journey for her and her family to get this matter to court.