So if you saw a body in the road would you stop?

This week, the Evening Standard featured shocking pictures of a young woman lying unconscious in the gutter of a busy road, blood pouring from a head injury. The worst thing about the CCTV images of the 25-year-old's plight was the string of cars that swerved past her small and helpless figure - and then drove on.

The case highlighted the apparent unwillingness of Londoners to play Good Samaritan.

So the Standard decided to test the readiness of people in the capital to help out in an emergency. The results were distinctly depressing.

We asked student Katy Walford, 20, to help with the experiment. She was asked to lie, in broad daylight, by a path in Kensington Gardens as though she had either been taken ill or attacked.

Then the reactions of passers by to her plight were monitored.

Three quarters of them simply strolled past her prone figure - many pretending not to notice her at all.

In total, of the 50 people who passed her during a busy lunchtime period, just 13 stopped. Of those, only two knelt down next to Katy and a third tapped her on the shoulder. The rest asked if she was okay but kept their distance.

Katy said: "I was really surprised that more people didn't stop. I don't think I looked particularly threatening - I am a 20-year-old woman.

"While about four of the people who stopped looked genuinely concerned, most just appeared suspicious or bewildered by me. If something awful had happened to me, crucial minutes would have been lost by people simply pretending they couldn't see me.

"I don't understand what reason there could be not to stop and help someone."

Of those who stopped, most were in groups or pairs. None of the teenagers or elderly people who passed offered to help.

A middle-aged jogger who did stop after a moment of brief hesitation said: "It was alarming to see a young woman lying on the path but I also wondered if it could be a trick. You have to be careful in London parks, especially after the recent murder in Richmond Park and stabbings elsewhere. It's a sad reflection on the state of society today." A woman in her thirties, who stopped to check on Katy, said she was shocked by people's attitudes. "It's totally outrageous," she said. "This girl obviously isn't some drunken tramp or criminal. She could have been injured or had an epileptic fit and be in need of medical assistance.

"It is disgraceful that you have all these full-grown men jogging by and pretending not to notice. They should feel very guilty. What has happened to people's morals? When you see a girl lying on the ground like this, your conscience should be telling you to stop."

Meanwhile, there are no further clues to the incident which prompted our experiment. A 25-year-old woman had collapsed in the road in Sidcup after suffering a severe head injury. CCTV images captured by an approaching bus showed that a stream of motorists drove around the woman as she lay across double yellow lines but did not stop to help.

It was the bus driver who finally raised the alarm, although it is not known exactly long she had been in the road.

Police believe the woman, who is of Chinese origin, had been the victim of a robbery. She was treated in a south London hospital and discharged on Tuesday.

Police plan to interview her when she is well enough.