A mystery Good Samaritan has been dubbed a hero after stopping a car rolling backwards into oncoming traffic - after the driver suffered a medical emergency at the wheel. 

A stunned passerby - who wanted to remain anonymous - told the Bucks Free Press he was near the chip shop on Mill End Road in High Wycombe on Thursday when he noticed a car rolling back down towards oncoming traffic. 

He then saw a man run over, open the driver's door, dive inside and pull up the handbrake - preventing a major crash. 

As the scene unfolded, it appeared that the driver - an elderly lady - was having a medical episode and was "fitting in the driver's seat". 

The passerby said: "I stopped, ran up and asked if I should call 999, he was already trying to help this lady and I spoke to emergency services. About five of us stopped and helped.

"When the emergency services came, the lady was very disoriented but conscious.

"I said to this guy, 'mate you're a hero, well done' then he told me he had, I think, paralysis of one leg and had run despite the fact he had trouble walking.

"He had stuck with this lady all the way through and gave me a hug then limped away shaken, full of adrenaline and I just feel compelled to say what a guy."

It has since been revealed that the hero is a delivery driver for Corner Plaice chip shop named Jason. 

Gary Wilson, who works at the chip shop, shared the news with the Bucks Free Press. 

Do you know the Good Samaritan who helped at the scene? Email stephanie.wareham@london.newsquest.co.uk or call 01494 755 096.