The frantic driver flagged down mounted policeman John Barron – who quickly dismounted from 18-hands-high Clyde and jumped aboard the single decker to tend to the stricken 72-year-old grandmother.

Diabetic Joan Guthrie, who was on the bus home from Hartlepool town centre, has now thanked her hero PC.

Joan, said: "Every little girl dreams of being rescued by a man on a horse, but not quite in those circumstances."

Joan, who was married to the late Ralph Guthrie, a Hartlepool United goalkeeper, slipped into a deep low blood sugar coma following a check-up appointment at a town clinic.

After doing some shopping, Joan boarded the bus in York Road to go to her home on the Brooke estate.

But the next thing she remembers is waking up in hospital.

Joan now believes that extra insulin she had taken that morning may have triggered the coma.

She said: "I can't remember anything from boarding the bus to waking up in hospital.

"A sister in the hospital who told me what had happened and that it was a policeman on a horse that had come to the rescue."

Joan soon discovered that after slipping into the coma the bus driver raised the alarm in the King Oswy area after finding her unconscious.

The bus driver alerted PC Barron who was on patrol near the shops. The driver held on to the horse while he jumped on board.

He checked Joan's bag and after finding information inidcating she was diabetic he got someone to go and buy a Mars Bar.

He said: "I managed to give her some Mars Bar followed by some glucose tablets I found in her bag.

"The bus driver had called the paramedics and they arrived soon after. By that point she was semi conscious."

Joan was taken to the University Hospital of Hartlepool and was released the same evening.

The next morning Joan was shocked when she received a call from PC Barron who wanted to check she was OK.

And to show her thanks she delivered a Mars Bar Easter egg to the station.

Joan said: "It just goes to show that there are good people are out there.

"Not everyone gets out of these comas so I am very grateful to him."

PC Barron said: "I have never had to deal with a situation like that, but I thought if I looked in her bag it might give me an idea of what was wrong. Once I knew it was diabetes it was OK, but I was glad to see the ambulance arrive.

"I was more than glad to be able to help and it was very sweet of her to bring in the Easter egg."