THE foreman of a jury which convicted Scots serial killer nurse, Colin Norris, has said he now believes he is innocent.

Norris, 38, was jailed for life in 2008 for murdering four patients and attempting to kill a fifth at hospitals in Leeds.

Juror Paul Moffitt spoke out after an investigation by the BBC's Panorama suggested the women may have died of natural causes.

He said he doubted the case would even come to court on the evidence available today. He is the second member of the jury to admit he doubts Norris' conviction.

Mr Moffitt, 36, said: "If this case was presented with this new evidence today, I don't even know how it could possibly get to court in the first place."

Norris, from Glasgow, was convicted at Newcastle Crown Court in 2008 following a five month-long trial. He was given a life sentence with a minimum term of 30 years, and is imprisoned at HMP Frankland in County Durham.

He was found guilty of murdering Doris Ludlam, 80, Bridget Bourke, 88, Irene Crookes, 79, and 86-year-old Ethel Hall.

He was alleged to have injected them with lethal doses of insulin at Leeds General Infirmary and the city's St James's Hospital in 2002.

He was also found guilty of attempting to murder Vera Wilby, 90.

However, a series of experts have challenged the evidence used to convict Norris.

Prof Terry Wilkin, an endocrinologist from the University of Exeter, Dr Adel Ismail, a retired clinical biochemist, and insulin poisoning expert Prof Vincent Mark all cast doubt of the safety of the conviction during the Panorama documentary broadcast in December.

For example, a blood test from Ms Hall had suggested a high level of insulin in her system. However, it was suggested that an "unrealistic" amount of injected insulin - just over one litre - would have been needed to produce the blood-test result.

They also argued that a rare condition called insulin auto-immune syndrome, rather than foul play, could have explained the blood-test. Furthermore, they stressed that hypoglycaemia - an abnormally low level of blood glucose - occurs naturally in up to 10 per cent of sick, elderly people so a cluster of cases would not necessarily suggest murder, as the prosecution had claimed.

The programme also reported that a sixth case, of a patient who died after a similar hypoglycaemic episode, was not put to the jury after detectives discounted it when they realised that Norris had not been on shift at the time.

Mr Moffitt said he believed the new evidence "shows that a murder wasn't committed at all, never mind four or one attempted murder".

He added that if the convictions were overturned the case would probably be remembered as one of the "biggest ever" miscarriages of justice in British legal history.

Mr Moffitt said: "I'd like to see Colin Norris freed. That's why I came forward, put my name forward, I just felt it would be my duty to do that."

The Criminal Cases Review Commission is considering whether the case merits an appeal, but some relatives of the women who died say they are still convinced of Norris's guilt.

A spokesman for the commission said: "The commission is actively reviewing the case.

"It is not possible to give an estimate as to how long our investigation will take, not least because we are still receiving submissions from Mr Norris' representatives."