The final two children who remained in hospital following the E.coli outbreak at a Surrey farm have finally been allowed home, more than a month after the site was shut down by health officials.

The Health Protection Agency (HPA) said on Tuesday that the total number of E.coli cases linked to Godstone Farm still stood at 93, adding that "all children have been discharged from hospital."

Twin brothers Aaron and Todd Furnell, from Paddock Wood in Kent (right) underwent dialysis at St Thomas's Hospital in London after falling ill with the O157 strain of the infection following a visit to Godstone Farm.

Two-year old Aaron Furnell spent six weeks in hospital; he still has to be fed food through a tube.

The site closed on September 12, two weeks after the first case of E.coli was reported there.

A third out of 102 samples taken from animals were found to contain E.coli 0157, and the chief executive of the HPA, Justin McCracken, admitted the agency should have acted quicker in shutting the farm.

An independent investigation has been commissioned and will be led by George Griffin, professor of infectious diseases and medicine at St George’s, University of London, and chair of the advisory committee on dangerous pathogens.

Families affected will be asked if they want to have their say during the probe, which will look at how Godstone Farm was being operated, according to the standards and guidance set for open farms, and the response to the outbreak from all relevant parties.

Legal action is also being planned by some parents of children who were left seriously ill.

A spokesman for Godstone Farm said a decision on when the site will re-open could be made later this week.