The parents of a two-year-old boy have spoken of their horror after the child wandered out of his nursery unnoticed and followed his mother for half a mile through traffic-choked streets.

At the time the toddler left the nursery, there were three staff members looking after four children. He crossed four roads unsupervised before being stopped by a member of the public.

Latha Srinivasagopalan, of Browning Avenue, Worcester Park, dropped her son Girish off at Daisy Chain Nursery, Ruskin Drive, at 9.10am last Thursday.

After informing a member of staff she had left Girish who began playing with toys she went out of the nursery and towards shops in Central Road.

Unknown to her, however, Girish also walked out of the nursery and followed her as she went to the end of Ruskin Drive and turned right.

Nursery staff did not notice his absence until he was out of sight and his potentially disastrous journey had been halted by a good Samaritan who saw him being narrowly missed by cars.

The owner of the nursery, John Azah, told the Sutton Guardian the incident was a mistake and procedures had already been tightened.

"It happened in a split second and we had a number of things happening that morning with a number of people needing attention," he said.

"We've had the nursery for two years. Nothing like this has happened before and it will never happen again."

However, Girish's parents have now moved him from the nursery which he had been attending for four days.

Mrs Srinivasagopalan, 36, said: "I left him inside and told a woman before coming out so I didn't have the slightest idea he was behind me.

"It was drizzling a little bit so I was walking quickly because I didn't have an umbrella. I didn't even look behind me because you are confident your child is in the nursery.

"Once I realised what had happened and that he had crossed so many roads I was really shocked and started crying.

"I can't imagine something happening to him. He was following along behind me and there was every chance of him being hit by a vehicle."

Girish's followed his mother up Cheam Common Road and Central Road, and across Lindsay Road, St Philip's Avenue, Brinkley Road and Washington Road, which all join the main road.

The danger was finally averted when a motorist noticed Girish walking perilously close to cars, stopped her own vehicle and took hold of him.

The woman left the toddler with a member of the public before approaching Mrs Srinivasagopalan as she was crossing Central Road by Worcester Park Library.

Initially the woman thought Girish had been deliberately abandoned and questioned Mrs Srinivasagopalan before driving the mother and son back to the nursery.

Mrs Srinivasagopalan added: "She told me he was crossing the road just when a car was coming and she told me the vehicle was coming very quickly. The traffic was heavy at the time it was 9.20am."

Mrs Srinivasagopalan and her husband Ravi, who are both doctors, only moved to Worcester Park in August.

Mr Srinivasagopalan, 41, added: "If this can happen to my child today, this can happen to any child tomorrow."