An investigation has been launched after a child was left behind at the zoo after a school trip.

The three-year-old boy, who goes to KidStuff Nursery, in Shenley Road, had spent the day at London Zoo with his classmates on Wednesday, September 9.

But he did not make it back onto the coach at the end of the day with the rest of the group - and teachers did not realise.

It was only discovered he was missing when the bus got back to Borehamwood 35 minutes later and the boy’s mother was waiting for him.

Frantic calls were made to police, and it turned out the boy was already being looked after by officers at the zoo.

Malcolm, the joint owner of KidStuff, refused to give his surname when quizzed about the incident by the Borehamwood Times.

But he did confirm it happened and said it is currently being investigated.

He said: “It was resolved fairly quickly, there were no problems in the end.

“I don’t know exactly what happened because I wasn’t on the coach.

“But I can confirm it did happen and that’s all I am prepared to say on the matter at the moment.

“We are seriously investigating it.

“Until the outcome of any investigation I am not prepared to make more of a comment.”

The school’s policy is to ensure one adult is responsible for three children during day trips and it is not known how the boy became unaccounted for.

One mother who had been considering sending her child to the nursery says the incident has left her too afraid.

She said: “I think people and parents need to know about what happened.

“How can you loose a child in that way and not even realise until you get back to the school?

“Anyone could have taken this child. I am so unhappy about hearing this.

“As a mum myself, I can’t imagine what his mum went through.

“I don’t feel safe sending my child to that nursery anymore.

“I am just happy he was found safe.”

Ofsted have now launched an investigation into what happened at the privately-run centre.

In its last Ofsted report, carried out in January 2014, the school’s rating jumped from ‘requires improvement’ to ‘good’.

In a statement the Metropolitan Police said: "Police received a report of a missing child at London Zoo at shortly before 1500hrs on 9 September.

"A four-year-old boy had become separated from his carers.

"The child was reunited with his mother at 4.20pm."