A pensioner who broke his kneecap after falling in a city subway is urging the council to investigate the safety of Canterbury's underpasses.

Retired policeman Len Hinksman, 70, was on his way to the shops from his home in New Dover Road when he slipped on the downslope of the subway near the Odeon cinema, falling heavily onto the ground.

"I found myself completely immobile and in considerable pain," he said.

"I didn't know it at the time but I had suffered a fractured patella in my right knee."

Mr Hinksman, who used to work for the Metropolitan Police, says the ground was damp as a result of recent rain and his footing just went from beneath him.

"I thought it was meant to be a non-slip surface but it's clearly far from it, and since my accident I have heard of others who have also slipped," he said.

"Fortunately, several passers-by came to my aid because I couldn't move."

Because his injuries were not life-threatening, Mr Hinksman says he was told he may have to wait for two hours for an ambulance.

But after two police officers arrived on the scene and saw the distress he was in, paramedics were asked to arrive more promptly.

"My knee came up the size of a football and I had to have surgery soon after, " said Mr Hinksman, who is a volunteer classroom assistant at Pilgrims Way School.

"Now I have a long recovery, which is very frustrating because I am normally very active. Earlier this year I was mountain biking in New Zealand, where my daughter lives."

Mr Hinksman, a grandfather who lives with his partner Sue, is now urging the city council to examine the surface.

"My GP at the Canterbury Medical Practice told me I was the second person that he knew who had recently suffered a similar fate," he said.

"And several people have since told me they have found the underpass slopes to be treacherous.

"I am taking legal advice but it's more about getting the council to do something about it than the money."

Mr Hinksman, who also works with a charity to refurbish tools, says he wrote to council chief executive Colin Carmichael to express his concerns about the subway surface.

Council spokesman Rob Davies said: "We were concerned to hear from Mr Hinksman about this incident and send him our best wishes for a speedy recovery.

"We have already sent him a reply to say we take the issue very seriously and will investigate what happened. He indicated he intends to take advice on further action in due course and we will be happy to deal with any further queries at that time."

Read more: All the latest news from Canterbury