Furious parents demanded answers yesterday after it emerged that a Surrey farm popular with children was kept open for two weeks despite being hit by an E.coli outbreak.

Thirty-six people, including 12 children have been taken ill since the first case was confirmed at Godstone Farm on August 27.

Three youngsters currently remain in a serious condition.

The Health Protection Agency said a series of non-contact measures introduced on September 3 should have been sufficient to contain the disease.

Tracy Mock from Kent, told the BBC her two-year-old twin boys were admitted to hospital since visiting the farm near Redhill on August 31. Her five-year-old daughter is also ill.

"If they had just shut the place down to investigate, my sons would not be in hospital on kidney dialysis machines," she said.

"They are still in hospital, my partner and I are taking turns to be there with them. One has had a blood transfusion. The doctors say it could be weeks until they are in a fit state to come home," she added.

Evelina Niedzwiedzka, 28, also went to the farm a fortnight ago with her one-year-old daughter.

"If the farm did know about it two weeks ago, I'm very surprised there were no warnings, especially because children are so vulnerable," she said.

A HPA spokesman defended the agency's response as "adequate".

"This action has been taken in previous incidents and is both a proportionate and effective response for the scale of incident at that stage."

Farm manager Richard Oatway said the farm was cooperating with the investigation.

"All the staff at the farm are very upset about the E.coli outbreak and we hope that all the children make a full and speedy recovery."