Godstone Farm was closed to the public on Saturday
Five more people have contracted E.coli in an outbreak linked to a children's farm in Surrey.
Of 45 confirmed cases, 12 are children being treated in hospital. Four of them are seriously ill, six are in a stable condition and two more are improving.
Godstone Farm was closed to the public on Saturday following the outbreak.
Its sister farm, Horton Park in Epsom, closed voluntarily after the Health Protection Agency (HPA) found hygiene arrangements to be unsatisfactory.
The HPA advised the local authority that the farm be closed immediately while the "defects were rectified".
A spokeswoman for Horton Park Children's Farm said the decision to close the farm on Wednesday evening was made because of the perceived "slight risk" of more children contracting E.coli.
The letter displayed at the entrance to the farm said it had closed as a temporary measure "owing to concerns expressed by us and others, and due to the slight risk to our customers of the chance of disease".
HPA officials are not aware of any cases of E.coli linked to Horton Park farm.
Since the outbreak the HPA has apologised to parents for delays in closing Godstone Farm and an independent investigation has begun.